1Enterococcosel AgarA selective and differential medium that inhibits the growth of Gram-negative bacteria and distinguishes enterococci based on their ability to grow in the presence of bile and hydrolyze esculin. E. faecalis will form small, black colonies on this medium due to esculin hydrolysis.
2Cornmeal Agar with Tween 80It is used for the identification of Candida species by promoting the formation of chlamydospores, which is a characteristic of Candida albicans.
3Simmons Citrate AgarUsed for citrate utilization testing. E. coli usually can't utilize citrate as a sole carbon source, so no growth or color change would be expected.
4Petragnini MediumAn egg-based medium enriched with additional nutrients to promote the growth of Mycobacterium tuberculosis. Colonies of M. tuberculosis are small, round, buff-colored, and typically take 3-4 weeks to appear.
5Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
6Blood Agar (BA)E. coli colonies on this differential medium are large, circular, gray, moist, and can show β-hemolysis.
7Phenol Red Mannitol BrothThis is a differential medium, used to determine an organism's ability to ferment mannitol. S. aureus, which can ferment mannitol, will change the medium from red to yellow due to acid production.
8Middlebrook 7H10 AgarA selective medium that contains oleic acid, albumin, dextrose, and catalase. The colonies of M. tuberculosis appear small, rough, and buff to white-colored, taking less time to appear compared to egg-based media.
9RPMI 1640 MediumIt is a rich medium that contains inorganic salts, glucose, amino acids, vitamins, and other nutrients that promote the growth of yeast cells.
10Middlebrook 7H11 AgarThis is a nutrient-rich medium similar to 7H10 but includes additional pyruvate for energy source, promoting more luxurious growth. The colonies of M. tuberculosis appear small, slightly domed, and rough with a butyrous consistency.
11Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
12Dorset MediumAn egg-based medium. M. tuberculosis colonies appear similar to those on Petragnini Medium: small, round, buff-colored, and taking 3-4 weeks to develop.
13MacConkey Agar (MAC)This selective and differential medium distinguishes lactose fermenters from non-fermenters. E. coli colonies are circular, moist, smooth, and pink.
14Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
15Loeffler MediumA serum-based medium. M. tuberculosis colonies on Loeffler medium are small, dry, wrinkled, and off-white to yellow.
16Azide Dextrose BrothA selective medium inhibiting Gram-negative bacteria, used for the isolation of streptococci and staphylococci from mixed samples. E. faecalis will show a positive growth resulting in a turbid appearance of the broth.
17Brain-Heart Infusion (BHI) Broth or AgarThis is a nutrient-rich medium that supports the growth of a variety of fastidious organisms, including E. faecalis. The typical phenotype of E. faecalis on BHI is small, round, and white colonies.
18Tryptic Soy Broth or Agar (TSB/TSA)A general-purpose medium that supports the growth of a broad spectrum of bacteria. E. faecalis on TSA will typically form small, round, and white colonies, indicating a positive growth.
19Lowenstein-Jensen (LJ) MediumAn egg-based medium that uses malachite green to suppress the growth of other bacteria and glycerol to stimulate the growth of Mycobacterium tuberculosis. The colonies of M. tuberculosis on LJ are non-pigmented, dry, rough, raised, irregular with a wrinkled surface, initially creamy-white, turning yellowish or buff-colored on further incubation.
20MacConkey AgarTraditionally used to isolate and differentiate Gram-negative bacilli, E. faecalis can grow on this medium, producing small, round, magenta pink colonies due to lactose fermentation, indicating a positive result.
21Lysine Iron Agar (LIA)Used to determine the ability of an organism to decarboxylate or deaminate lysine and to form hydrogen sulfide. E. coli is typically lysine decarboxylase positive and H2S negative, so you would see a reaction of red/purple slant and purple/red butt with no black precipitate.
22m-ENDO AgarE. coli colonies appear as green with a metallic sheen, indicating lactose fermentation.
23Cystine Lactose Electrolyte-Deficient (CLED) AgarE. coli will give lactose-positive yellow colonies.
24Nutrient AgarIt is a general-purpose medium. However, E. faecalis grows poorly on nutrient agar, which means it does not proliferate as well on this medium compared to the others listed, indicating a negative or poor growth.
25Liquid Media (such as Nutrient Broth)E. coli exhibits homogenous turbid growth within 12-18 hours. After prolonged incubation, pellicles may form on the surface of the media.
26Potato Dextrose Agar (PDA)Potato Dextrose Agar (PDA) consists of a nutrient-rich substrate, made from dehydrated Potato Infusion and Dextrose, ideal for robust mycological propagation. Agar provides the solidifying medium. Acidification, typically using sterile tartaric acid, adjusts the pH to 3.5 +/- 0.1 to create a more selective environment by inhibiting bacterial proliferation. Additionally, Chloramphenicol is incorporated as an antimicrobial agent to further suppress bacterial contamination, thereby facilitating the selective isolation of fungi.
27Sorbitol-MacConkey agarA variant of MacConkey agar, used in detecting E. coli O157:H7, which does not ferment sorbitol, unlike most strains of E. coli.
28Sauton’s MediumA liquid medium that lacks detergents, which helps in the formation of corded colonies. When M. tuberculosis grows in this medium, it results in turbidity.
29DNase Test AgarS. aureus produces the enzyme DNase which hydrolyses DNA. When S. aureus grows on this medium, the DNA is broken down, which can be visualised using a hydrochloric acid (HCl) solution: clear zones around the colonies indicate DNA breakdown.
30Baird-Parker Agar (BPA)his is a selective medium for the isolation of Staphylococcus species. It has lithium chloride and glycine to inhibit the growth of Gram-negative bacteria and most Gram-positive bacteria except Staphylococcus. Egg yolk emulsion is added to detect lecithinase production and tellurite reduction. S. aureus colonies on BPA are black due to reduction of tellurite, and they exhibit a clear zone due to lecithinase activity on egg yolk.
31Proskauer and Beck’s MediumA liquid medium. The growth of M. tuberculosis causes turbidity.
32Middlebrook 7H9 BrothThis is a liquid medium that contains glycerol and Tween 80, which prevent clumping of mycobacteria. The growth of M. tuberculosis results in turbidity.
33Tryptic Soy Agar (TSA)A general purpose medium. E. coli colonies are medium to large, with a shiny moist appearance.
34Dubos’ MediumA liquid medium that contains a mixture of salts, fatty acids, and polysorbate. When M. tuberculosis grows in this medium, it causes the medium to become turbid.
35Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in this medium.
36Triple Sugar Iron (TSI) AgarE. coli typically produces an acid butt, acid slant, and gas, with no H2S production, indicating it ferments lactose, sucrose, and glucose.
37Bile Esculin Agar (BEA)A selective and differential medium that differentiates group D Streptococci and Enterococci based on the ability to hydrolyze esculin in the presence of bile. E. faecalis hydrolyzes esculin, leading to the formation of a dark brown or black precipita
38Brilliant Green Agar (BGA)A selective medium that is used to isolate Salmonella species, but E. coli can grow on it, albeit not as well.
39Blood AgarA differential medium used to identify bacteria based on their hemolytic properties. E. faecalis typically shows gamma-hemolysis on this medium, i.e., no hemolysis or change in the color of the medium.
40Todd-Hewitt BrothA liquid enrichment medium used for the cultivation of fastidious organisms such as streptococci and enterococci. E. faecalis will lead to a turbid broth due to microbial growth.
41Sula’s MediumA liquid medium containing glycerol, asparagine, and a variety of salts. The growth of M. tuberculosis results in turbidity.
42Nickerson’s Medium or Bismuth Sulfite Glucose Glycine Yeast (BSGG)This medium is used to stimulate the production of germ tubes, a characteristic of Candida albicans.
43Sf1Ep mediumCulturing Treponema pallidum, the bacteria that causes syphilis, in vitro is a challenge. T. pallidum is not routinely cultured in the laboratory for diagnostic purposes, in part because it cannot be grown on artificial media. However, a breakthrough in culturing T. pallidum was reported in 2018 when researchers managed to grow the bacterium in a rabbit epithelial cell line (Sf1Ep) using a medium called 'Sf1Ep medium'. It's not used for routine diagnostic purposes, but for research only. The diagnosis involves direct microscopic examination, serologic tests, molecular tests and histopathology.
44Blood Agar (BA)This is a nutrient-rich, differential medium that supports the growth of many organisms. S. aureus forms colonies that are round, smooth, and golden-yellow. This bacterium typically demonstrates β-hemolysis, which is complete lysis of red blood cells, resulting in a clear zone around the colonies. This hemolysis is due to the production of hemolysins by S. aureus.
45CHROMagar CandidaThis differential medium allows for the isolation and identification of Candida species based on colony color. Candida albicans usually forms green colonies on this medium.
46Sabouraud Dextrose Agar (SDA)It is composed of peptone, dextrose (glucose), and agar. The high dextrose concentration promotes fungal growth, while the acidic pH inhibits bacterial growth.
47BACTECThis is not a traditional medium but a system for detecting the growth of M. tuberculosis by monitoring the release of C14O2 from C14 palmitic acid, which the bacteria metabolize. An increase in radioactive counts in the BACTEC instrument indicates the growth of bacteria.
48Tarshis MediumA blood-based medium that can promote the growth of M. tuberculosis. The colonies appear similar to those on the LJ Medium.
49Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
50Violet Red Bile Agar (VRBA)E. coli colonies are red (pink to red) and may show bluish fluorescence under UV light.
1Simmons Citrate AgarUsed for citrate utilization testing. E. coli usually can't utilize citrate as a sole carbon source, so no growth or color change would be expected.
2Phenol Red Mannitol BrothThis is a differential medium, used to determine an organism's ability to ferment mannitol. S. aureus, which can ferment mannitol, will change the medium from red to yellow due to acid production.
3Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
4RPMI 1640 MediumIt is a rich medium that contains inorganic salts, glucose, amino acids, vitamins, and other nutrients that promote the growth of yeast cells.
5Middlebrook 7H10 AgarA selective medium that contains oleic acid, albumin, dextrose, and catalase. The colonies of M. tuberculosis appear small, rough, and buff to white-colored, taking less time to appear compared to egg-based media.
6Middlebrook 7H11 AgarThis is a nutrient-rich medium similar to 7H10 but includes additional pyruvate for energy source, promoting more luxurious growth. The colonies of M. tuberculosis appear small, slightly domed, and rough with a butyrous consistency.
7MacConkey Agar (MAC)This selective and differential medium distinguishes lactose fermenters from non-fermenters. E. coli colonies are circular, moist, smooth, and pink.
8Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
9Dorset MediumAn egg-based medium. M. tuberculosis colonies appear similar to those on Petragnini Medium: small, round, buff-colored, and taking 3-4 weeks to develop.
10Sf1Ep mediumCulturing Treponema pallidum, the bacteria that causes syphilis, in vitro is a challenge. T. pallidum is not routinely cultured in the laboratory for diagnostic purposes, in part because it cannot be grown on artificial media. However, a breakthrough in culturing T. pallidum was reported in 2018 when researchers managed to grow the bacterium in a rabbit epithelial cell line (Sf1Ep) using a medium called 'Sf1Ep medium'. It's not used for routine diagnostic purposes, but for research only. The diagnosis involves direct microscopic examination, serologic tests, molecular tests and histopathology.
11Blood Agar (BA)E. coli colonies on this differential medium are large, circular, gray, moist, and can show β-hemolysis.
12Brain-Heart Infusion (BHI) Broth or AgarThis is a nutrient-rich medium that supports the growth of a variety of fastidious organisms, including E. faecalis. The typical phenotype of E. faecalis on BHI is small, round, and white colonies.
13Loeffler MediumA serum-based medium. M. tuberculosis colonies on Loeffler medium are small, dry, wrinkled, and off-white to yellow.
14Azide Dextrose BrothA selective medium inhibiting Gram-negative bacteria, used for the isolation of streptococci and staphylococci from mixed samples. E. faecalis will show a positive growth resulting in a turbid appearance of the broth.
15Mannitol Salt Agar (MSA), or Chapman AgarThis is a selective and differential medium. The high concentration of NaCl (~7.5%) selects for halophiles, organisms that can tolerate high salt concentrations, thereby favouring the growth of Staphylococcus species. Mannitol is the differential component: S. aureus ferments mannitol, lowering the pH of the medium, which results in a color change of the pH indicator from red to yellow. Thus, growth of S. aureus is indicated by yellow colonies.
16Tryptic Soy Broth or Agar (TSB/TSA)A general-purpose medium that supports the growth of a broad spectrum of bacteria. E. faecalis on TSA will typically form small, round, and white colonies, indicating a positive growth.
17Middlebrook 7H9 BrothThis is a liquid medium that contains glycerol and Tween 80, which prevent clumping of mycobacteria. The growth of M. tuberculosis results in turbidity.
18Lowenstein-Jensen (LJ) MediumAn egg-based medium that uses malachite green to suppress the growth of other bacteria and glycerol to stimulate the growth of Mycobacterium tuberculosis. The colonies of M. tuberculosis on LJ are non-pigmented, dry, rough, raised, irregular with a wrinkled surface, initially creamy-white, turning yellowish or buff-colored on further incubation.
19MacConkey AgarTraditionally used to isolate and differentiate Gram-negative bacilli, E. faecalis can grow on this medium, producing small, round, magenta pink colonies due to lactose fermentation, indicating a positive result.
20Lysine Iron Agar (LIA)Used to determine the ability of an organism to decarboxylate or deaminate lysine and to form hydrogen sulfide. E. coli is typically lysine decarboxylase positive and H2S negative, so you would see a reaction of red/purple slant and purple/red butt with no black precipitate.
21Sauton’s MediumA liquid medium that lacks detergents, which helps in the formation of corded colonies. When M. tuberculosis grows in this medium, it results in turbidity.
22CHROMagar CandidaThis differential medium allows for the isolation and identification of Candida species based on colony color. Candida albicans usually forms green colonies on this medium.
23Nickerson’s Medium or Bismuth Sulfite Glucose Glycine Yeast (BSGG)This medium is used to stimulate the production of germ tubes, a characteristic of Candida albicans.
24Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in this medium.
25Bile Esculin Agar (BEA)A selective and differential medium that differentiates group D Streptococci and Enterococci based on the ability to hydrolyze esculin in the presence of bile. E. faecalis hydrolyzes esculin, leading to the formation of a dark brown or black precipita
26Sula’s MediumA liquid medium containing glycerol, asparagine, and a variety of salts. The growth of M. tuberculosis results in turbidity.
27Triple Sugar Iron (TSI) AgarE. coli typically produces an acid butt, acid slant, and gas, with no H2S production, indicating it ferments lactose, sucrose, and glucose.
28Blood AgarA differential medium used to identify bacteria based on their hemolytic properties. E. faecalis typically shows gamma-hemolysis on this medium, i.e., no hemolysis or change in the color of the medium.
29Sorbitol-MacConkey agarA variant of MacConkey agar, used in detecting E. coli O157:H7, which does not ferment sorbitol, unlike most strains of E. coli.
30Nutrient AgarIt is a general-purpose medium. However, E. faecalis grows poorly on nutrient agar, which means it does not proliferate as well on this medium compared to the others listed, indicating a negative or poor growth.
31Liquid Media (such as Nutrient Broth)E. coli exhibits homogenous turbid growth within 12-18 hours. After prolonged incubation, pellicles may form on the surface of the media.
32Sabouraud Dextrose Agar (SDA)It is composed of peptone, dextrose (glucose), and agar. The high dextrose concentration promotes fungal growth, while the acidic pH inhibits bacterial growth.
33Potato Dextrose Agar (PDA)Potato Dextrose Agar (PDA) consists of a nutrient-rich substrate, made from dehydrated Potato Infusion and Dextrose, ideal for robust mycological propagation. Agar provides the solidifying medium. Acidification, typically using sterile tartaric acid, adjusts the pH to 3.5 +/- 0.1 to create a more selective environment by inhibiting bacterial proliferation. Additionally, Chloramphenicol is incorporated as an antimicrobial agent to further suppress bacterial contamination, thereby facilitating the selective isolation of fungi.
34DNase Test AgarS. aureus produces the enzyme DNase which hydrolyses DNA. When S. aureus grows on this medium, the DNA is broken down, which can be visualised using a hydrochloric acid (HCl) solution: clear zones around the colonies indicate DNA breakdown.
35BACTECThis is not a traditional medium but a system for detecting the growth of M. tuberculosis by monitoring the release of C14O2 from C14 palmitic acid, which the bacteria metabolize. An increase in radioactive counts in the BACTEC instrument indicates the growth of bacteria.
36Tryptic Soy Agar (TSA)A general purpose medium. E. coli colonies are medium to large, with a shiny moist appearance.
37Dubos’ MediumA liquid medium that contains a mixture of salts, fatty acids, and polysorbate. When M. tuberculosis grows in this medium, it causes the medium to become turbid.
38Proskauer and Beck’s MediumA liquid medium. The growth of M. tuberculosis causes turbidity.
39Tarshis MediumA blood-based medium that can promote the growth of M. tuberculosis. The colonies appear similar to those on the LJ Medium.
40m-ENDO AgarE. coli colonies appear as green with a metallic sheen, indicating lactose fermentation.
41Todd-Hewitt BrothA liquid enrichment medium used for the cultivation of fastidious organisms such as streptococci and enterococci. E. faecalis will lead to a turbid broth due to microbial growth.
42Enterococcosel AgarA selective and differential medium that inhibits the growth of Gram-negative bacteria and distinguishes enterococci based on their ability to grow in the presence of bile and hydrolyze esculin. E. faecalis will form small, black colonies on this medium due to esculin hydrolysis.
43Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
44Cornmeal Agar with Tween 80It is used for the identification of Candida species by promoting the formation of chlamydospores, which is a characteristic of Candida albicans.
45Petragnini MediumAn egg-based medium enriched with additional nutrients to promote the growth of Mycobacterium tuberculosis. Colonies of M. tuberculosis are small, round, buff-colored, and typically take 3-4 weeks to appear.
46Blood Agar (BA)This is a nutrient-rich, differential medium that supports the growth of many organisms. S. aureus forms colonies that are round, smooth, and golden-yellow. This bacterium typically demonstrates β-hemolysis, which is complete lysis of red blood cells, resulting in a clear zone around the colonies. This hemolysis is due to the production of hemolysins by S. aureus.
47Cystine Lactose Electrolyte-Deficient (CLED) AgarE. coli will give lactose-positive yellow colonies.
48Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
49Brilliant Green Agar (BGA)A selective medium that is used to isolate Salmonella species, but E. coli can grow on it, albeit not as well.
1Potato Dextrose Agar (PDA)Potato Dextrose Agar (PDA) consists of a nutrient-rich substrate, made from dehydrated Potato Infusion and Dextrose, ideal for robust mycological propagation. Agar provides the solidifying medium. Acidification, typically using sterile tartaric acid, adjusts the pH to 3.5 +/- 0.1 to create a more selective environment by inhibiting bacterial proliferation. Additionally, Chloramphenicol is incorporated as an antimicrobial agent to further suppress bacterial contamination, thereby facilitating the selective isolation of fungi.
2DNase Test AgarS. aureus produces the enzyme DNase which hydrolyses DNA. When S. aureus grows on this medium, the DNA is broken down, which can be visualised using a hydrochloric acid (HCl) solution: clear zones around the colonies indicate DNA breakdown.
3Blood Agar (BA)This is a nutrient-rich, differential medium that supports the growth of many organisms. S. aureus forms colonies that are round, smooth, and golden-yellow. This bacterium typically demonstrates β-hemolysis, which is complete lysis of red blood cells, resulting in a clear zone around the colonies. This hemolysis is due to the production of hemolysins by S. aureus.
4Cystine Lactose Electrolyte-Deficient (CLED) AgarE. coli will give lactose-positive yellow colonies.
5Baird-Parker Agar (BPA)his is a selective medium for the isolation of Staphylococcus species. It has lithium chloride and glycine to inhibit the growth of Gram-negative bacteria and most Gram-positive bacteria except Staphylococcus. Egg yolk emulsion is added to detect lecithinase production and tellurite reduction. S. aureus colonies on BPA are black due to reduction of tellurite, and they exhibit a clear zone due to lecithinase activity on egg yolk.
6Middlebrook 7H9 BrothThis is a liquid medium that contains glycerol and Tween 80, which prevent clumping of mycobacteria. The growth of M. tuberculosis results in turbidity.
7Tryptic Soy Agar (TSA)A general purpose medium. E. coli colonies are medium to large, with a shiny moist appearance.
8Blood Agar (BA)E. coli colonies on this differential medium are large, circular, gray, moist, and can show β-hemolysis.
9Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
10Sf1Ep mediumCulturing Treponema pallidum, the bacteria that causes syphilis, in vitro is a challenge. T. pallidum is not routinely cultured in the laboratory for diagnostic purposes, in part because it cannot be grown on artificial media. However, a breakthrough in culturing T. pallidum was reported in 2018 when researchers managed to grow the bacterium in a rabbit epithelial cell line (Sf1Ep) using a medium called 'Sf1Ep medium'. It's not used for routine diagnostic purposes, but for research only. The diagnosis involves direct microscopic examination, serologic tests, molecular tests and histopathology.
11Loeffler MediumA serum-based medium. M. tuberculosis colonies on Loeffler medium are small, dry, wrinkled, and off-white to yellow.
12Azide Dextrose BrothA selective medium inhibiting Gram-negative bacteria, used for the isolation of streptococci and staphylococci from mixed samples. E. faecalis will show a positive growth resulting in a turbid appearance of the broth.
13Mannitol Salt Agar (MSA), or Chapman AgarThis is a selective and differential medium. The high concentration of NaCl (~7.5%) selects for halophiles, organisms that can tolerate high salt concentrations, thereby favouring the growth of Staphylococcus species. Mannitol is the differential component: S. aureus ferments mannitol, lowering the pH of the medium, which results in a color change of the pH indicator from red to yellow. Thus, growth of S. aureus is indicated by yellow colonies.
14Violet Red Bile Agar (VRBA)E. coli colonies are red (pink to red) and may show bluish fluorescence under UV light.
15Tryptic Soy Broth or Agar (TSB/TSA)A general-purpose medium that supports the growth of a broad spectrum of bacteria. E. faecalis on TSA will typically form small, round, and white colonies, indicating a positive growth.
16Lowenstein-Jensen (LJ) MediumAn egg-based medium that uses malachite green to suppress the growth of other bacteria and glycerol to stimulate the growth of Mycobacterium tuberculosis. The colonies of M. tuberculosis on LJ are non-pigmented, dry, rough, raised, irregular with a wrinkled surface, initially creamy-white, turning yellowish or buff-colored on further incubation.
17Lysine Iron Agar (LIA)Used to determine the ability of an organism to decarboxylate or deaminate lysine and to form hydrogen sulfide. E. coli is typically lysine decarboxylase positive and H2S negative, so you would see a reaction of red/purple slant and purple/red butt with no black precipitate.
18MacConkey AgarTraditionally used to isolate and differentiate Gram-negative bacilli, E. faecalis can grow on this medium, producing small, round, magenta pink colonies due to lactose fermentation, indicating a positive result.
19m-ENDO AgarE. coli colonies appear as green with a metallic sheen, indicating lactose fermentation.
20Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
21Sauton’s MediumA liquid medium that lacks detergents, which helps in the formation of corded colonies. When M. tuberculosis grows in this medium, it results in turbidity.
22Sorbitol-MacConkey agarA variant of MacConkey agar, used in detecting E. coli O157:H7, which does not ferment sorbitol, unlike most strains of E. coli.
23Nutrient AgarIt is a general-purpose medium. However, E. faecalis grows poorly on nutrient agar, which means it does not proliferate as well on this medium compared to the others listed, indicating a negative or poor growth.
24RPMI 1640 MediumIt is a rich medium that contains inorganic salts, glucose, amino acids, vitamins, and other nutrients that promote the growth of yeast cells.
25Middlebrook 7H10 AgarA selective medium that contains oleic acid, albumin, dextrose, and catalase. The colonies of M. tuberculosis appear small, rough, and buff to white-colored, taking less time to appear compared to egg-based media.
26Middlebrook 7H11 AgarThis is a nutrient-rich medium similar to 7H10 but includes additional pyruvate for energy source, promoting more luxurious growth. The colonies of M. tuberculosis appear small, slightly domed, and rough with a butyrous consistency.
27CHROMagar CandidaThis differential medium allows for the isolation and identification of Candida species based on colony color. Candida albicans usually forms green colonies on this medium.
28Liquid Media (such as Nutrient Broth)E. coli exhibits homogenous turbid growth within 12-18 hours. After prolonged incubation, pellicles may form on the surface of the media.
29MacConkey Agar (MAC)This selective and differential medium distinguishes lactose fermenters from non-fermenters. E. coli colonies are circular, moist, smooth, and pink.
30Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
31Dorset MediumAn egg-based medium. M. tuberculosis colonies appear similar to those on Petragnini Medium: small, round, buff-colored, and taking 3-4 weeks to develop.
32Brain-Heart Infusion (BHI) Broth or AgarThis is a nutrient-rich medium that supports the growth of a variety of fastidious organisms, including E. faecalis. The typical phenotype of E. faecalis on BHI is small, round, and white colonies.
33Enterococcosel AgarA selective and differential medium that inhibits the growth of Gram-negative bacteria and distinguishes enterococci based on their ability to grow in the presence of bile and hydrolyze esculin. E. faecalis will form small, black colonies on this medium due to esculin hydrolysis.
34Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
35Cornmeal Agar with Tween 80It is used for the identification of Candida species by promoting the formation of chlamydospores, which is a characteristic of Candida albicans.
36Petragnini MediumAn egg-based medium enriched with additional nutrients to promote the growth of Mycobacterium tuberculosis. Colonies of M. tuberculosis are small, round, buff-colored, and typically take 3-4 weeks to appear.
37Simmons Citrate AgarUsed for citrate utilization testing. E. coli usually can't utilize citrate as a sole carbon source, so no growth or color change would be expected.
38Nickerson’s Medium or Bismuth Sulfite Glucose Glycine Yeast (BSGG)This medium is used to stimulate the production of germ tubes, a characteristic of Candida albicans.
39Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in this medium.
40Sula’s MediumA liquid medium containing glycerol, asparagine, and a variety of salts. The growth of M. tuberculosis results in turbidity.
41Triple Sugar Iron (TSI) AgarE. coli typically produces an acid butt, acid slant, and gas, with no H2S production, indicating it ferments lactose, sucrose, and glucose.
42Blood AgarA differential medium used to identify bacteria based on their hemolytic properties. E. faecalis typically shows gamma-hemolysis on this medium, i.e., no hemolysis or change in the color of the medium.
43Todd-Hewitt BrothA liquid enrichment medium used for the cultivation of fastidious organisms such as streptococci and enterococci. E. faecalis will lead to a turbid broth due to microbial growth.
44BACTECThis is not a traditional medium but a system for detecting the growth of M. tuberculosis by monitoring the release of C14O2 from C14 palmitic acid, which the bacteria metabolize. An increase in radioactive counts in the BACTEC instrument indicates the growth of bacteria.
45Brilliant Green Agar (BGA)A selective medium that is used to isolate Salmonella species, but E. coli can grow on it, albeit not as well.
46Bile Esculin Agar (BEA)A selective and differential medium that differentiates group D Streptococci and Enterococci based on the ability to hydrolyze esculin in the presence of bile. E. faecalis hydrolyzes esculin, leading to the formation of a dark brown or black precipita
1Blood Agar (BA)This is a nutrient-rich, differential medium that supports the growth of many organisms. S. aureus forms colonies that are round, smooth, and golden-yellow. This bacterium typically demonstrates β-hemolysis, which is complete lysis of red blood cells, resulting in a clear zone around the colonies. This hemolysis is due to the production of hemolysins by S. aureus.
2Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in this medium.
3Azide Dextrose BrothA selective medium inhibiting Gram-negative bacteria, used for the isolation of streptococci and staphylococci from mixed samples. E. faecalis will show a positive growth resulting in a turbid appearance of the broth.
4Baird-Parker Agar (BPA)his is a selective medium for the isolation of Staphylococcus species. It has lithium chloride and glycine to inhibit the growth of Gram-negative bacteria and most Gram-positive bacteria except Staphylococcus. Egg yolk emulsion is added to detect lecithinase production and tellurite reduction. S. aureus colonies on BPA are black due to reduction of tellurite, and they exhibit a clear zone due to lecithinase activity on egg yolk.
5Middlebrook 7H9 BrothThis is a liquid medium that contains glycerol and Tween 80, which prevent clumping of mycobacteria. The growth of M. tuberculosis results in turbidity.
6Cystine Lactose Electrolyte-Deficient (CLED) AgarE. coli will give lactose-positive yellow colonies.
7CHROMagar CandidaThis differential medium allows for the isolation and identification of Candida species based on colony color. Candida albicans usually forms green colonies on this medium.
8Nickerson’s Medium or Bismuth Sulfite Glucose Glycine Yeast (BSGG)This medium is used to stimulate the production of germ tubes, a characteristic of Candida albicans.
9Sauton’s MediumA liquid medium that lacks detergents, which helps in the formation of corded colonies. When M. tuberculosis grows in this medium, it results in turbidity.
10Tryptic Soy Agar (TSA)A general purpose medium. E. coli colonies are medium to large, with a shiny moist appearance.
11Proskauer and Beck’s MediumA liquid medium. The growth of M. tuberculosis causes turbidity.
12Tarshis MediumA blood-based medium that can promote the growth of M. tuberculosis. The colonies appear similar to those on the LJ Medium.
13Dubos’ MediumA liquid medium that contains a mixture of salts, fatty acids, and polysorbate. When M. tuberculosis grows in this medium, it causes the medium to become turbid.
14Tryptic Soy Broth or Agar (TSB/TSA)A general-purpose medium that supports the growth of a broad spectrum of bacteria. E. faecalis on TSA will typically form small, round, and white colonies, indicating a positive growth.
15m-ENDO AgarE. coli colonies appear as green with a metallic sheen, indicating lactose fermentation.
16Lowenstein-Jensen (LJ) MediumAn egg-based medium that uses malachite green to suppress the growth of other bacteria and glycerol to stimulate the growth of Mycobacterium tuberculosis. The colonies of M. tuberculosis on LJ are non-pigmented, dry, rough, raised, irregular with a wrinkled surface, initially creamy-white, turning yellowish or buff-colored on further incubation.
17MacConkey AgarTraditionally used to isolate and differentiate Gram-negative bacilli, E. faecalis can grow on this medium, producing small, round, magenta pink colonies due to lactose fermentation, indicating a positive result.
18Lysine Iron Agar (LIA)Used to determine the ability of an organism to decarboxylate or deaminate lysine and to form hydrogen sulfide. E. coli is typically lysine decarboxylase positive and H2S negative, so you would see a reaction of red/purple slant and purple/red butt with no black precipitate.
19Nutrient AgarIt is a general-purpose medium. However, E. faecalis grows poorly on nutrient agar, which means it does not proliferate as well on this medium compared to the others listed, indicating a negative or poor growth.
20Liquid Media (such as Nutrient Broth)E. coli exhibits homogenous turbid growth within 12-18 hours. After prolonged incubation, pellicles may form on the surface of the media.
21Sorbitol-MacConkey agarA variant of MacConkey agar, used in detecting E. coli O157:H7, which does not ferment sorbitol, unlike most strains of E. coli.
22Sabouraud Dextrose Agar (SDA)It is composed of peptone, dextrose (glucose), and agar. The high dextrose concentration promotes fungal growth, while the acidic pH inhibits bacterial growth.
23Loeffler MediumA serum-based medium. M. tuberculosis colonies on Loeffler medium are small, dry, wrinkled, and off-white to yellow.
24Brain-Heart Infusion (BHI) Broth or AgarThis is a nutrient-rich medium that supports the growth of a variety of fastidious organisms, including E. faecalis. The typical phenotype of E. faecalis on BHI is small, round, and white colonies.
25Mannitol Salt Agar (MSA), or Chapman AgarThis is a selective and differential medium. The high concentration of NaCl (~7.5%) selects for halophiles, organisms that can tolerate high salt concentrations, thereby favouring the growth of Staphylococcus species. Mannitol is the differential component: S. aureus ferments mannitol, lowering the pH of the medium, which results in a color change of the pH indicator from red to yellow. Thus, growth of S. aureus is indicated by yellow colonies.
26Potato Dextrose Agar (PDA)Potato Dextrose Agar (PDA) consists of a nutrient-rich substrate, made from dehydrated Potato Infusion and Dextrose, ideal for robust mycological propagation. Agar provides the solidifying medium. Acidification, typically using sterile tartaric acid, adjusts the pH to 3.5 +/- 0.1 to create a more selective environment by inhibiting bacterial proliferation. Additionally, Chloramphenicol is incorporated as an antimicrobial agent to further suppress bacterial contamination, thereby facilitating the selective isolation of fungi.
27Simmons Citrate AgarUsed for citrate utilization testing. E. coli usually can't utilize citrate as a sole carbon source, so no growth or color change would be expected.
28Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
29Phenol Red Mannitol BrothThis is a differential medium, used to determine an organism's ability to ferment mannitol. S. aureus, which can ferment mannitol, will change the medium from red to yellow due to acid production.
30Middlebrook 7H10 AgarA selective medium that contains oleic acid, albumin, dextrose, and catalase. The colonies of M. tuberculosis appear small, rough, and buff to white-colored, taking less time to appear compared to egg-based media.
31RPMI 1640 MediumIt is a rich medium that contains inorganic salts, glucose, amino acids, vitamins, and other nutrients that promote the growth of yeast cells.
32Middlebrook 7H11 AgarThis is a nutrient-rich medium similar to 7H10 but includes additional pyruvate for energy source, promoting more luxurious growth. The colonies of M. tuberculosis appear small, slightly domed, and rough with a butyrous consistency.
33Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
34Sf1Ep mediumCulturing Treponema pallidum, the bacteria that causes syphilis, in vitro is a challenge. T. pallidum is not routinely cultured in the laboratory for diagnostic purposes, in part because it cannot be grown on artificial media. However, a breakthrough in culturing T. pallidum was reported in 2018 when researchers managed to grow the bacterium in a rabbit epithelial cell line (Sf1Ep) using a medium called 'Sf1Ep medium'. It's not used for routine diagnostic purposes, but for research only. The diagnosis involves direct microscopic examination, serologic tests, molecular tests and histopathology.
35MacConkey Agar (MAC)This selective and differential medium distinguishes lactose fermenters from non-fermenters. E. coli colonies are circular, moist, smooth, and pink.
36Blood Agar (BA)E. coli colonies on this differential medium are large, circular, gray, moist, and can show β-hemolysis.
37Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
38Enterococcosel AgarA selective and differential medium that inhibits the growth of Gram-negative bacteria and distinguishes enterococci based on their ability to grow in the presence of bile and hydrolyze esculin. E. faecalis will form small, black colonies on this medium due to esculin hydrolysis.
39Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
40Dorset MediumAn egg-based medium. M. tuberculosis colonies appear similar to those on Petragnini Medium: small, round, buff-colored, and taking 3-4 weeks to develop.
41Cornmeal Agar with Tween 80It is used for the identification of Candida species by promoting the formation of chlamydospores, which is a characteristic of Candida albicans.
42Violet Red Bile Agar (VRBA)E. coli colonies are red (pink to red) and may show bluish fluorescence under UV light.
43Petragnini MediumAn egg-based medium enriched with additional nutrients to promote the growth of Mycobacterium tuberculosis. Colonies of M. tuberculosis are small, round, buff-colored, and typically take 3-4 weeks to appear.
44BACTECThis is not a traditional medium but a system for detecting the growth of M. tuberculosis by monitoring the release of C14O2 from C14 palmitic acid, which the bacteria metabolize. An increase in radioactive counts in the BACTEC instrument indicates the growth of bacteria.
1Cystine Lactose Electrolyte-Deficient (CLED) AgarE. coli will give lactose-positive yellow colonies.
2CHROMagar CandidaThis differential medium allows for the isolation and identification of Candida species based on colony color. Candida albicans usually forms green colonies on this medium.
3Baird-Parker Agar (BPA)his is a selective medium for the isolation of Staphylococcus species. It has lithium chloride and glycine to inhibit the growth of Gram-negative bacteria and most Gram-positive bacteria except Staphylococcus. Egg yolk emulsion is added to detect lecithinase production and tellurite reduction. S. aureus colonies on BPA are black due to reduction of tellurite, and they exhibit a clear zone due to lecithinase activity on egg yolk.
4Tryptic Soy Agar (TSA)A general purpose medium. E. coli colonies are medium to large, with a shiny moist appearance.
5Proskauer and Beck’s MediumA liquid medium. The growth of M. tuberculosis causes turbidity.
6Dubos’ MediumA liquid medium that contains a mixture of salts, fatty acids, and polysorbate. When M. tuberculosis grows in this medium, it causes the medium to become turbid.
7m-ENDO AgarE. coli colonies appear as green with a metallic sheen, indicating lactose fermentation.
8Potato Dextrose Agar (PDA)Potato Dextrose Agar (PDA) consists of a nutrient-rich substrate, made from dehydrated Potato Infusion and Dextrose, ideal for robust mycological propagation. Agar provides the solidifying medium. Acidification, typically using sterile tartaric acid, adjusts the pH to 3.5 +/- 0.1 to create a more selective environment by inhibiting bacterial proliferation. Additionally, Chloramphenicol is incorporated as an antimicrobial agent to further suppress bacterial contamination, thereby facilitating the selective isolation of fungi.
9Tryptic Soy Broth or Agar (TSB/TSA)A general-purpose medium that supports the growth of a broad spectrum of bacteria. E. faecalis on TSA will typically form small, round, and white colonies, indicating a positive growth.
10BACTECThis is not a traditional medium but a system for detecting the growth of M. tuberculosis by monitoring the release of C14O2 from C14 palmitic acid, which the bacteria metabolize. An increase in radioactive counts in the BACTEC instrument indicates the growth of bacteria.
11Blood Agar (BA)This is a nutrient-rich, differential medium that supports the growth of many organisms. S. aureus forms colonies that are round, smooth, and golden-yellow. This bacterium typically demonstrates β-hemolysis, which is complete lysis of red blood cells, resulting in a clear zone around the colonies. This hemolysis is due to the production of hemolysins by S. aureus.
12Lowenstein-Jensen (LJ) MediumAn egg-based medium that uses malachite green to suppress the growth of other bacteria and glycerol to stimulate the growth of Mycobacterium tuberculosis. The colonies of M. tuberculosis on LJ are non-pigmented, dry, rough, raised, irregular with a wrinkled surface, initially creamy-white, turning yellowish or buff-colored on further incubation.
13MacConkey AgarTraditionally used to isolate and differentiate Gram-negative bacilli, E. faecalis can grow on this medium, producing small, round, magenta pink colonies due to lactose fermentation, indicating a positive result.
14Lysine Iron Agar (LIA)Used to determine the ability of an organism to decarboxylate or deaminate lysine and to form hydrogen sulfide. E. coli is typically lysine decarboxylase positive and H2S negative, so you would see a reaction of red/purple slant and purple/red butt with no black precipitate.
15Nutrient AgarIt is a general-purpose medium. However, E. faecalis grows poorly on nutrient agar, which means it does not proliferate as well on this medium compared to the others listed, indicating a negative or poor growth.
16Middlebrook 7H9 BrothThis is a liquid medium that contains glycerol and Tween 80, which prevent clumping of mycobacteria. The growth of M. tuberculosis results in turbidity.
17Liquid Media (such as Nutrient Broth)E. coli exhibits homogenous turbid growth within 12-18 hours. After prolonged incubation, pellicles may form on the surface of the media.
18Sorbitol-MacConkey agarA variant of MacConkey agar, used in detecting E. coli O157:H7, which does not ferment sorbitol, unlike most strains of E. coli.
19Sabouraud Dextrose Agar (SDA)It is composed of peptone, dextrose (glucose), and agar. The high dextrose concentration promotes fungal growth, while the acidic pH inhibits bacterial growth.
20Middlebrook 7H11 AgarThis is a nutrient-rich medium similar to 7H10 but includes additional pyruvate for energy source, promoting more luxurious growth. The colonies of M. tuberculosis appear small, slightly domed, and rough with a butyrous consistency.
21MacConkey Agar (MAC)This selective and differential medium distinguishes lactose fermenters from non-fermenters. E. coli colonies are circular, moist, smooth, and pink.
22Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
23Dorset MediumAn egg-based medium. M. tuberculosis colonies appear similar to those on Petragnini Medium: small, round, buff-colored, and taking 3-4 weeks to develop.
24Sf1Ep mediumCulturing Treponema pallidum, the bacteria that causes syphilis, in vitro is a challenge. T. pallidum is not routinely cultured in the laboratory for diagnostic purposes, in part because it cannot be grown on artificial media. However, a breakthrough in culturing T. pallidum was reported in 2018 when researchers managed to grow the bacterium in a rabbit epithelial cell line (Sf1Ep) using a medium called 'Sf1Ep medium'. It's not used for routine diagnostic purposes, but for research only. The diagnosis involves direct microscopic examination, serologic tests, molecular tests and histopathology.
25Blood Agar (BA)E. coli colonies on this differential medium are large, circular, gray, moist, and can show β-hemolysis.
26Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
27Brain-Heart Infusion (BHI) Broth or AgarThis is a nutrient-rich medium that supports the growth of a variety of fastidious organisms, including E. faecalis. The typical phenotype of E. faecalis on BHI is small, round, and white colonies.
28Sauton’s MediumA liquid medium that lacks detergents, which helps in the formation of corded colonies. When M. tuberculosis grows in this medium, it results in turbidity.
29Loeffler MediumA serum-based medium. M. tuberculosis colonies on Loeffler medium are small, dry, wrinkled, and off-white to yellow.
30Azide Dextrose BrothA selective medium inhibiting Gram-negative bacteria, used for the isolation of streptococci and staphylococci from mixed samples. E. faecalis will show a positive growth resulting in a turbid appearance of the broth.
31Enterococcosel AgarA selective and differential medium that inhibits the growth of Gram-negative bacteria and distinguishes enterococci based on their ability to grow in the presence of bile and hydrolyze esculin. E. faecalis will form small, black colonies on this medium due to esculin hydrolysis.
32Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
33Cornmeal Agar with Tween 80It is used for the identification of Candida species by promoting the formation of chlamydospores, which is a characteristic of Candida albicans.
34Petragnini MediumAn egg-based medium enriched with additional nutrients to promote the growth of Mycobacterium tuberculosis. Colonies of M. tuberculosis are small, round, buff-colored, and typically take 3-4 weeks to appear.
35Violet Red Bile Agar (VRBA)E. coli colonies are red (pink to red) and may show bluish fluorescence under UV light.
36Simmons Citrate AgarUsed for citrate utilization testing. E. coli usually can't utilize citrate as a sole carbon source, so no growth or color change would be expected.
37Phenol Red Mannitol BrothThis is a differential medium, used to determine an organism's ability to ferment mannitol. S. aureus, which can ferment mannitol, will change the medium from red to yellow due to acid production.
38Tarshis MediumA blood-based medium that can promote the growth of M. tuberculosis. The colonies appear similar to those on the LJ Medium.
39Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
40RPMI 1640 MediumIt is a rich medium that contains inorganic salts, glucose, amino acids, vitamins, and other nutrients that promote the growth of yeast cells.
41Middlebrook 7H10 AgarA selective medium that contains oleic acid, albumin, dextrose, and catalase. The colonies of M. tuberculosis appear small, rough, and buff to white-colored, taking less time to appear compared to egg-based media.
42Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in this medium.
43Bile Esculin Agar (BEA)A selective and differential medium that differentiates group D Streptococci and Enterococci based on the ability to hydrolyze esculin in the presence of bile. E. faecalis hydrolyzes esculin, leading to the formation of a dark brown or black precipita
44Sula’s MediumA liquid medium containing glycerol, asparagine, and a variety of salts. The growth of M. tuberculosis results in turbidity.
45Triple Sugar Iron (TSI) AgarE. coli typically produces an acid butt, acid slant, and gas, with no H2S production, indicating it ferments lactose, sucrose, and glucose.
46Blood AgarA differential medium used to identify bacteria based on their hemolytic properties. E. faecalis typically shows gamma-hemolysis on this medium, i.e., no hemolysis or change in the color of the medium.
47Todd-Hewitt BrothA liquid enrichment medium used for the cultivation of fastidious organisms such as streptococci and enterococci. E. faecalis will lead to a turbid broth due to microbial growth.
48Brilliant Green Agar (BGA)A selective medium that is used to isolate Salmonella species, but E. coli can grow on it, albeit not as well.
1Cystine Lactose Electrolyte-Deficient (CLED) AgarE. coli will give lactose-positive yellow colonies.
2CHROMagar CandidaThis differential medium allows for the isolation and identification of Candida species based on colony color. Candida albicans usually forms green colonies on this medium.
3Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in this medium.
4BACTECThis is not a traditional medium but a system for detecting the growth of M. tuberculosis by monitoring the release of C14O2 from C14 palmitic acid, which the bacteria metabolize. An increase in radioactive counts in the BACTEC instrument indicates the growth of bacteria.
5Baird-Parker Agar (BPA)his is a selective medium for the isolation of Staphylococcus species. It has lithium chloride and glycine to inhibit the growth of Gram-negative bacteria and most Gram-positive bacteria except Staphylococcus. Egg yolk emulsion is added to detect lecithinase production and tellurite reduction. S. aureus colonies on BPA are black due to reduction of tellurite, and they exhibit a clear zone due to lecithinase activity on egg yolk.
6Middlebrook 7H9 BrothThis is a liquid medium that contains glycerol and Tween 80, which prevent clumping of mycobacteria. The growth of M. tuberculosis results in turbidity.
7Dubos’ MediumA liquid medium that contains a mixture of salts, fatty acids, and polysorbate. When M. tuberculosis grows in this medium, it causes the medium to become turbid.
8Tarshis MediumA blood-based medium that can promote the growth of M. tuberculosis. The colonies appear similar to those on the LJ Medium.
9m-ENDO AgarE. coli colonies appear as green with a metallic sheen, indicating lactose fermentation.
10Azide Dextrose BrothA selective medium inhibiting Gram-negative bacteria, used for the isolation of streptococci and staphylococci from mixed samples. E. faecalis will show a positive growth resulting in a turbid appearance of the broth.
11Middlebrook 7H11 AgarThis is a nutrient-rich medium similar to 7H10 but includes additional pyruvate for energy source, promoting more luxurious growth. The colonies of M. tuberculosis appear small, slightly domed, and rough with a butyrous consistency.
12Proskauer and Beck’s MediumA liquid medium. The growth of M. tuberculosis causes turbidity.
13Mannitol Salt Agar (MSA), or Chapman AgarThis is a selective and differential medium. The high concentration of NaCl (~7.5%) selects for halophiles, organisms that can tolerate high salt concentrations, thereby favouring the growth of Staphylococcus species. Mannitol is the differential component: S. aureus ferments mannitol, lowering the pH of the medium, which results in a color change of the pH indicator from red to yellow. Thus, growth of S. aureus is indicated by yellow colonies.
14Tryptic Soy Broth or Agar (TSB/TSA)A general-purpose medium that supports the growth of a broad spectrum of bacteria. E. faecalis on TSA will typically form small, round, and white colonies, indicating a positive growth.
15Tryptic Soy Agar (TSA)A general purpose medium. E. coli colonies are medium to large, with a shiny moist appearance.
16Lowenstein-Jensen (LJ) MediumAn egg-based medium that uses malachite green to suppress the growth of other bacteria and glycerol to stimulate the growth of Mycobacterium tuberculosis. The colonies of M. tuberculosis on LJ are non-pigmented, dry, rough, raised, irregular with a wrinkled surface, initially creamy-white, turning yellowish or buff-colored on further incubation.
17MacConkey AgarTraditionally used to isolate and differentiate Gram-negative bacilli, E. faecalis can grow on this medium, producing small, round, magenta pink colonies due to lactose fermentation, indicating a positive result.
18Lysine Iron Agar (LIA)Used to determine the ability of an organism to decarboxylate or deaminate lysine and to form hydrogen sulfide. E. coli is typically lysine decarboxylase positive and H2S negative, so you would see a reaction of red/purple slant and purple/red butt with no black precipitate.
19Nutrient AgarIt is a general-purpose medium. However, E. faecalis grows poorly on nutrient agar, which means it does not proliferate as well on this medium compared to the others listed, indicating a negative or poor growth.
20Liquid Media (such as Nutrient Broth)E. coli exhibits homogenous turbid growth within 12-18 hours. After prolonged incubation, pellicles may form on the surface of the media.
21Sorbitol-MacConkey agarA variant of MacConkey agar, used in detecting E. coli O157:H7, which does not ferment sorbitol, unlike most strains of E. coli.
22Sauton’s MediumA liquid medium that lacks detergents, which helps in the formation of corded colonies. When M. tuberculosis grows in this medium, it results in turbidity.
23Potato Dextrose Agar (PDA)Potato Dextrose Agar (PDA) consists of a nutrient-rich substrate, made from dehydrated Potato Infusion and Dextrose, ideal for robust mycological propagation. Agar provides the solidifying medium. Acidification, typically using sterile tartaric acid, adjusts the pH to 3.5 +/- 0.1 to create a more selective environment by inhibiting bacterial proliferation. Additionally, Chloramphenicol is incorporated as an antimicrobial agent to further suppress bacterial contamination, thereby facilitating the selective isolation of fungi.
24Sabouraud Dextrose Agar (SDA)It is composed of peptone, dextrose (glucose), and agar. The high dextrose concentration promotes fungal growth, while the acidic pH inhibits bacterial growth.
25RPMI 1640 MediumIt is a rich medium that contains inorganic salts, glucose, amino acids, vitamins, and other nutrients that promote the growth of yeast cells.
26Middlebrook 7H10 AgarA selective medium that contains oleic acid, albumin, dextrose, and catalase. The colonies of M. tuberculosis appear small, rough, and buff to white-colored, taking less time to appear compared to egg-based media.
27MacConkey Agar (MAC)This selective and differential medium distinguishes lactose fermenters from non-fermenters. E. coli colonies are circular, moist, smooth, and pink.
28Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
29Dorset MediumAn egg-based medium. M. tuberculosis colonies appear similar to those on Petragnini Medium: small, round, buff-colored, and taking 3-4 weeks to develop.
30Sf1Ep mediumCulturing Treponema pallidum, the bacteria that causes syphilis, in vitro is a challenge. T. pallidum is not routinely cultured in the laboratory for diagnostic purposes, in part because it cannot be grown on artificial media. However, a breakthrough in culturing T. pallidum was reported in 2018 when researchers managed to grow the bacterium in a rabbit epithelial cell line (Sf1Ep) using a medium called 'Sf1Ep medium'. It's not used for routine diagnostic purposes, but for research only. The diagnosis involves direct microscopic examination, serologic tests, molecular tests and histopathology.
31Blood Agar (BA)E. coli colonies on this differential medium are large, circular, gray, moist, and can show β-hemolysis.
32Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
33Brain-Heart Infusion (BHI) Broth or AgarThis is a nutrient-rich medium that supports the growth of a variety of fastidious organisms, including E. faecalis. The typical phenotype of E. faecalis on BHI is small, round, and white colonies.
34Enterococcosel AgarA selective and differential medium that inhibits the growth of Gram-negative bacteria and distinguishes enterococci based on their ability to grow in the presence of bile and hydrolyze esculin. E. faecalis will form small, black colonies on this medium due to esculin hydrolysis.
35Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
36Cornmeal Agar with Tween 80It is used for the identification of Candida species by promoting the formation of chlamydospores, which is a characteristic of Candida albicans.
37Simmons Citrate AgarUsed for citrate utilization testing. E. coli usually can't utilize citrate as a sole carbon source, so no growth or color change would be expected.
38Phenol Red Mannitol BrothThis is a differential medium, used to determine an organism's ability to ferment mannitol. S. aureus, which can ferment mannitol, will change the medium from red to yellow due to acid production.
39Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
40Bile Esculin Agar (BEA)A selective and differential medium that differentiates group D Streptococci and Enterococci based on the ability to hydrolyze esculin in the presence of bile. E. faecalis hydrolyzes esculin, leading to the formation of a dark brown or black precipita
41Sula’s MediumA liquid medium containing glycerol, asparagine, and a variety of salts. The growth of M. tuberculosis results in turbidity.
42Triple Sugar Iron (TSI) AgarE. coli typically produces an acid butt, acid slant, and gas, with no H2S production, indicating it ferments lactose, sucrose, and glucose.
43Violet Red Bile Agar (VRBA)E. coli colonies are red (pink to red) and may show bluish fluorescence under UV light.
44Blood AgarA differential medium used to identify bacteria based on their hemolytic properties. E. faecalis typically shows gamma-hemolysis on this medium, i.e., no hemolysis or change in the color of the medium.
45Brilliant Green Agar (BGA)A selective medium that is used to isolate Salmonella species, but E. coli can grow on it, albeit not as well.
46Todd-Hewitt BrothA liquid enrichment medium used for the cultivation of fastidious organisms such as streptococci and enterococci. E. faecalis will lead to a turbid broth due to microbial growth.
47DNase Test AgarS. aureus produces the enzyme DNase which hydrolyses DNA. When S. aureus grows on this medium, the DNA is broken down, which can be visualised using a hydrochloric acid (HCl) solution: clear zones around the colonies indicate DNA breakdown.
48Petragnini MediumAn egg-based medium enriched with additional nutrients to promote the growth of Mycobacterium tuberculosis. Colonies of M. tuberculosis are small, round, buff-colored, and typically take 3-4 weeks to appear.
1Tarshis MediumA blood-based medium that can promote the growth of M. tuberculosis. The colonies appear similar to those on the LJ Medium.
2m-ENDO AgarE. coli colonies appear as green with a metallic sheen, indicating lactose fermentation.
3Blood Agar (BA)This is a nutrient-rich, differential medium that supports the growth of many organisms. S. aureus forms colonies that are round, smooth, and golden-yellow. This bacterium typically demonstrates β-hemolysis, which is complete lysis of red blood cells, resulting in a clear zone around the colonies. This hemolysis is due to the production of hemolysins by S. aureus.
4Cystine Lactose Electrolyte-Deficient (CLED) AgarE. coli will give lactose-positive yellow colonies.
5CHROMagar CandidaThis differential medium allows for the isolation and identification of Candida species based on colony color. Candida albicans usually forms green colonies on this medium.
6Nickerson’s Medium or Bismuth Sulfite Glucose Glycine Yeast (BSGG)This medium is used to stimulate the production of germ tubes, a characteristic of Candida albicans.
7Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in this medium.
8Bile Esculin Agar (BEA)A selective and differential medium that differentiates group D Streptococci and Enterococci based on the ability to hydrolyze esculin in the presence of bile. E. faecalis hydrolyzes esculin, leading to the formation of a dark brown or black precipita
9Sula’s MediumA liquid medium containing glycerol, asparagine, and a variety of salts. The growth of M. tuberculosis results in turbidity.
10Triple Sugar Iron (TSI) AgarE. coli typically produces an acid butt, acid slant, and gas, with no H2S production, indicating it ferments lactose, sucrose, and glucose.
11Blood AgarA differential medium used to identify bacteria based on their hemolytic properties. E. faecalis typically shows gamma-hemolysis on this medium, i.e., no hemolysis or change in the color of the medium.
12Todd-Hewitt BrothA liquid enrichment medium used for the cultivation of fastidious organisms such as streptococci and enterococci. E. faecalis will lead to a turbid broth due to microbial growth.
13Brilliant Green Agar (BGA)A selective medium that is used to isolate Salmonella species, but E. coli can grow on it, albeit not as well.
14Enterococcosel AgarA selective and differential medium that inhibits the growth of Gram-negative bacteria and distinguishes enterococci based on their ability to grow in the presence of bile and hydrolyze esculin. E. faecalis will form small, black colonies on this medium due to esculin hydrolysis.
15Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
16Cornmeal Agar with Tween 80It is used for the identification of Candida species by promoting the formation of chlamydospores, which is a characteristic of Candida albicans.
17Brain-Heart Infusion (BHI) Broth or AgarThis is a nutrient-rich medium that supports the growth of a variety of fastidious organisms, including E. faecalis. The typical phenotype of E. faecalis on BHI is small, round, and white colonies.
18Potato Dextrose Agar (PDA)Potato Dextrose Agar (PDA) consists of a nutrient-rich substrate, made from dehydrated Potato Infusion and Dextrose, ideal for robust mycological propagation. Agar provides the solidifying medium. Acidification, typically using sterile tartaric acid, adjusts the pH to 3.5 +/- 0.1 to create a more selective environment by inhibiting bacterial proliferation. Additionally, Chloramphenicol is incorporated as an antimicrobial agent to further suppress bacterial contamination, thereby facilitating the selective isolation of fungi.
19Sabouraud Dextrose Agar (SDA)It is composed of peptone, dextrose (glucose), and agar. The high dextrose concentration promotes fungal growth, while the acidic pH inhibits bacterial growth.
20Sorbitol-MacConkey agarA variant of MacConkey agar, used in detecting E. coli O157:H7, which does not ferment sorbitol, unlike most strains of E. coli.
21DNase Test AgarS. aureus produces the enzyme DNase which hydrolyses DNA. When S. aureus grows on this medium, the DNA is broken down, which can be visualised using a hydrochloric acid (HCl) solution: clear zones around the colonies indicate DNA breakdown.
22BACTECThis is not a traditional medium but a system for detecting the growth of M. tuberculosis by monitoring the release of C14O2 from C14 palmitic acid, which the bacteria metabolize. An increase in radioactive counts in the BACTEC instrument indicates the growth of bacteria.
23Baird-Parker Agar (BPA)his is a selective medium for the isolation of Staphylococcus species. It has lithium chloride and glycine to inhibit the growth of Gram-negative bacteria and most Gram-positive bacteria except Staphylococcus. Egg yolk emulsion is added to detect lecithinase production and tellurite reduction. S. aureus colonies on BPA are black due to reduction of tellurite, and they exhibit a clear zone due to lecithinase activity on egg yolk.
24Middlebrook 7H9 BrothThis is a liquid medium that contains glycerol and Tween 80, which prevent clumping of mycobacteria. The growth of M. tuberculosis results in turbidity.
25Tryptic Soy Agar (TSA)A general purpose medium. E. coli colonies are medium to large, with a shiny moist appearance.
26Dubos’ MediumA liquid medium that contains a mixture of salts, fatty acids, and polysorbate. When M. tuberculosis grows in this medium, it causes the medium to become turbid.
27Nutrient AgarIt is a general-purpose medium. However, E. faecalis grows poorly on nutrient agar, which means it does not proliferate as well on this medium compared to the others listed, indicating a negative or poor growth.
28Liquid Media (such as Nutrient Broth)E. coli exhibits homogenous turbid growth within 12-18 hours. After prolonged incubation, pellicles may form on the surface of the media.
29Tryptic Soy Broth or Agar (TSB/TSA)A general-purpose medium that supports the growth of a broad spectrum of bacteria. E. faecalis on TSA will typically form small, round, and white colonies, indicating a positive growth.
30MacConkey AgarTraditionally used to isolate and differentiate Gram-negative bacilli, E. faecalis can grow on this medium, producing small, round, magenta pink colonies due to lactose fermentation, indicating a positive result.
31Lowenstein-Jensen (LJ) MediumAn egg-based medium that uses malachite green to suppress the growth of other bacteria and glycerol to stimulate the growth of Mycobacterium tuberculosis. The colonies of M. tuberculosis on LJ are non-pigmented, dry, rough, raised, irregular with a wrinkled surface, initially creamy-white, turning yellowish or buff-colored on further incubation.
32Lysine Iron Agar (LIA)Used to determine the ability of an organism to decarboxylate or deaminate lysine and to form hydrogen sulfide. E. coli is typically lysine decarboxylase positive and H2S negative, so you would see a reaction of red/purple slant and purple/red butt with no black precipitate.
33Middlebrook 7H10 AgarA selective medium that contains oleic acid, albumin, dextrose, and catalase. The colonies of M. tuberculosis appear small, rough, and buff to white-colored, taking less time to appear compared to egg-based media.
34Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
35Middlebrook 7H11 AgarThis is a nutrient-rich medium similar to 7H10 but includes additional pyruvate for energy source, promoting more luxurious growth. The colonies of M. tuberculosis appear small, slightly domed, and rough with a butyrous consistency.
36MacConkey Agar (MAC)This selective and differential medium distinguishes lactose fermenters from non-fermenters. E. coli colonies are circular, moist, smooth, and pink.
37Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
38Dorset MediumAn egg-based medium. M. tuberculosis colonies appear similar to those on Petragnini Medium: small, round, buff-colored, and taking 3-4 weeks to develop.
39Blood Agar (BA)E. coli colonies on this differential medium are large, circular, gray, moist, and can show β-hemolysis.
40Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
41Sf1Ep mediumCulturing Treponema pallidum, the bacteria that causes syphilis, in vitro is a challenge. T. pallidum is not routinely cultured in the laboratory for diagnostic purposes, in part because it cannot be grown on artificial media. However, a breakthrough in culturing T. pallidum was reported in 2018 when researchers managed to grow the bacterium in a rabbit epithelial cell line (Sf1Ep) using a medium called 'Sf1Ep medium'. It's not used for routine diagnostic purposes, but for research only. The diagnosis involves direct microscopic examination, serologic tests, molecular tests and histopathology.
42Loeffler MediumA serum-based medium. M. tuberculosis colonies on Loeffler medium are small, dry, wrinkled, and off-white to yellow.
43Azide Dextrose BrothA selective medium inhibiting Gram-negative bacteria, used for the isolation of streptococci and staphylococci from mixed samples. E. faecalis will show a positive growth resulting in a turbid appearance of the broth.
44Mannitol Salt Agar (MSA), or Chapman AgarThis is a selective and differential medium. The high concentration of NaCl (~7.5%) selects for halophiles, organisms that can tolerate high salt concentrations, thereby favouring the growth of Staphylococcus species. Mannitol is the differential component: S. aureus ferments mannitol, lowering the pH of the medium, which results in a color change of the pH indicator from red to yellow. Thus, growth of S. aureus is indicated by yellow colonies.