1Middlebrook 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.
2Tarshis MediumA blood-based medium that can promote the growth of M. tuberculosis. The colonies appear similar to those on the LJ Medium.
3Proskauer and Beck’s MediumA liquid medium. The growth of M. tuberculosis causes turbidity.
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.
6DNase 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.
7Sorbitol-MacConkey agarA variant of MacConkey agar, used in detecting E. coli O157:H7, which does not ferment sorbitol, unlike most strains of E. coli.
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.
9Liquid 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.
10Nutrient 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.
11Sauton’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.
12Lysine 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.
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.
14Lowenstein-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.
15Middlebrook 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.
16RPMI 1640 MediumIt is a rich medium that contains inorganic salts, glucose, amino acids, vitamins, and other nutrients that promote the growth of yeast cells.
17Phenol 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.
18Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
19Simmons 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.
20Violet Red Bile Agar (VRBA)E. coli colonies are red (pink to red) and may show bluish fluorescence under UV light.
21Petragnini 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.
22Cornmeal 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.
23Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
24Enterococcosel 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.
25CHROMagar 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.
26Cystine Lactose Electrolyte-Deficient (CLED) AgarE. coli will give lactose-positive yellow colonies.
27Mannitol 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.
28Tryptic 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.
29Sula’s MediumA liquid medium containing glycerol, asparagine, and a variety of salts. The growth of M. tuberculosis results in turbidity.
30Todd-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.
31Blood 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.
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.
33Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
34Dorset 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.
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.
37Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
38Middlebrook 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.
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.
40Brilliant Green Agar (BGA)A selective medium that is used to isolate Salmonella species, but E. coli can grow on it, albeit not as well.
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.
42Bile 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
43Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in this medium.
44Nickerson’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.
1m-ENDO AgarE. coli colonies appear as green with a metallic sheen, indicating lactose fermentation.
2Tarshis MediumA blood-based medium that can promote the growth of M. tuberculosis. The colonies appear similar to those on the LJ Medium.
3Tryptic Soy Agar (TSA)A general purpose medium. E. coli colonies are medium to large, with a shiny moist appearance.
4Proskauer and Beck’s MediumA liquid medium. The growth of M. tuberculosis causes turbidity.
5Dubos’ 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.
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.
7BACTECThis 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.
8DNase 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.
9Potato 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.
10Liquid 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.
11Sabouraud 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.
12Nutrient 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.
13Sorbitol-MacConkey agarA variant of MacConkey agar, used in detecting E. coli O157:H7, which does not ferment sorbitol, unlike most strains of E. coli.
14Sauton’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.
15Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
16Blood Agar (BA)E. coli colonies on this differential medium are large, circular, gray, moist, and can show β-hemolysis.
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.
18Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
19Dorset 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.
20Sf1Ep 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.
21MacConkey Agar (MAC)This selective and differential medium distinguishes lactose fermenters from non-fermenters. E. coli colonies are circular, moist, smooth, and pink.
22RPMI 1640 MediumIt is a rich medium that contains inorganic salts, glucose, amino acids, vitamins, and other nutrients that promote the growth of yeast cells.
23Middlebrook 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.
24Middlebrook 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.
25Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
26Phenol 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.
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.
28Violet Red Bile Agar (VRBA)E. coli colonies are red (pink to red) and may show bluish fluorescence under UV light.
29Petragnini 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.
30Nickerson’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.
31CHROMagar 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.
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.
33MacConkey 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.
34Lowenstein-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.
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.
36Cystine Lactose Electrolyte-Deficient (CLED) AgarE. coli will give lactose-positive yellow colonies.
37Tryptic 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.
38Mannitol 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.
39Azide 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.
40Loeffler MediumA serum-based medium. M. tuberculosis colonies on Loeffler medium are small, dry, wrinkled, and off-white to yellow.
41Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
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.
43Brilliant Green Agar (BGA)A selective medium that is used to isolate Salmonella species, but E. coli can grow on it, albeit not as well.
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.
45Todd-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.
46Triple 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.
47Sula’s MediumA liquid medium containing glycerol, asparagine, and a variety of salts. The growth of M. tuberculosis results in turbidity.
48Bile 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
49Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in this medium.
50Blood 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.
1m-ENDO AgarE. coli colonies appear as green with a metallic sheen, indicating lactose fermentation.
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.
3Potato 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.
4Sabouraud 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.
5Tryptic 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.
6Mannitol 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.
7Azide 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.
8Loeffler MediumA serum-based medium. M. tuberculosis colonies on Loeffler medium are small, dry, wrinkled, and off-white to yellow.
9Simmons 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.
10Petragnini 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.
11Violet Red Bile Agar (VRBA)E. coli colonies are red (pink to red) and may show bluish fluorescence under UV light.
12Cornmeal 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.
13Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
14Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in this medium.
15Nickerson’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.
16CHROMagar 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.
17Proskauer and Beck’s MediumA liquid medium. The growth of M. tuberculosis causes turbidity.
18Tarshis MediumA blood-based medium that can promote the growth of M. tuberculosis. The colonies appear similar to those on the LJ Medium.
19Dubos’ 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.
20Tryptic Soy Agar (TSA)A general purpose medium. E. coli colonies are medium to large, with a shiny moist appearance.
21Middlebrook 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.
22Baird-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.
23Liquid 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.
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.
25Sorbitol-MacConkey agarA variant of MacConkey agar, used in detecting E. coli O157:H7, which does not ferment sorbitol, unlike most strains of E. coli.
26Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
27Sf1Ep 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.
28Blood Agar (BA)E. coli colonies on this differential medium are large, circular, gray, moist, and can show β-hemolysis.
29Brain-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.
30Dorset 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.
31Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
32Enterococcosel 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.
33Cystine Lactose Electrolyte-Deficient (CLED) AgarE. coli will give lactose-positive yellow colonies.
34Blood 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.
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.
36Sauton’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.
37MacConkey 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.
38Lysine 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.
39Lowenstein-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.
40MacConkey Agar (MAC)This selective and differential medium distinguishes lactose fermenters from non-fermenters. E. coli colonies are circular, moist, smooth, and pink.
41Middlebrook 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.
42Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
43RPMI 1640 MediumIt is a rich medium that contains inorganic salts, glucose, amino acids, vitamins, and other nutrients that promote the growth of yeast cells.
44Middlebrook 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.
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.
47Triple 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.
48Blood 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.
49Sula’s MediumA liquid medium containing glycerol, asparagine, and a variety of salts. The growth of M. tuberculosis results in turbidity.
50Bile 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
1Sauton’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.
2Lysine 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.
3MacConkey 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.
4Lowenstein-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.
5Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
6Blood Agar (BA)E. coli colonies on this differential medium are large, circular, gray, moist, and can show β-hemolysis.
7Dorset 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.
8MacConkey Agar (MAC)This selective and differential medium distinguishes lactose fermenters from non-fermenters. E. coli colonies are circular, moist, smooth, and pink.
9Sf1Ep 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.
10Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
11Middlebrook 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.
12RPMI 1640 MediumIt is a rich medium that contains inorganic salts, glucose, amino acids, vitamins, and other nutrients that promote the growth of yeast cells.
13Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
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.
15Todd-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.
16Blood 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.
17Brilliant Green Agar (BGA)A selective medium that is used to isolate Salmonella species, but E. coli can grow on it, albeit not as well.
18Sula’s MediumA liquid medium containing glycerol, asparagine, and a variety of salts. The growth of M. tuberculosis results in turbidity.
19Triple 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.
20m-ENDO AgarE. coli colonies appear as green with a metallic sheen, indicating lactose fermentation.
21Bile 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
22Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in 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.
24CHROMagar 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.
25Dubos’ 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.
26Tarshis MediumA blood-based medium that can promote the growth of M. tuberculosis. The colonies appear similar to those on the LJ Medium.
27Tryptic Soy Agar (TSA)A general purpose medium. E. coli colonies are medium to large, with a shiny moist appearance.
28Proskauer and Beck’s MediumA liquid medium. The growth of M. tuberculosis causes turbidity.
29BACTECThis 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.
30Sabouraud 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.
31Potato 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.
32Sorbitol-MacConkey agarA variant of MacConkey agar, used in detecting E. coli O157:H7, which does not ferment sorbitol, unlike most strains of E. coli.
33Nutrient 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.
34Liquid 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.
35Tryptic 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.
36Mannitol 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.
37Azide 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.
38Brain-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.
39Loeffler MediumA serum-based medium. M. tuberculosis colonies on Loeffler medium are small, dry, wrinkled, and off-white to yellow.
40Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
41Simmons 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.
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.
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.
45Cystine Lactose Electrolyte-Deficient (CLED) AgarE. coli will give lactose-positive yellow colonies.
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.
1m-ENDO AgarE. coli colonies appear as green with a metallic sheen, indicating lactose fermentation.
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.
3Potato 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.
4Lowenstein-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.
5Tryptic 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.
6Middlebrook 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.
7RPMI 1640 MediumIt is a rich medium that contains inorganic salts, glucose, amino acids, vitamins, and other nutrients that promote the growth of yeast cells.
8Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
9Phenol 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.
10Simmons 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.
11Triple 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.
12Sula’s MediumA liquid medium containing glycerol, asparagine, and a variety of salts. The growth of M. tuberculosis results in turbidity.
13Bile 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
14Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in this medium.
15Nickerson’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.
16Dubos’ 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.
17Proskauer and Beck’s MediumA liquid medium. The growth of M. tuberculosis causes turbidity.
18Middlebrook 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.
19Tryptic Soy Agar (TSA)A general purpose medium. E. coli colonies are medium to large, with a shiny moist appearance.
20Sabouraud 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.
21Azide 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.
22Loeffler MediumA serum-based medium. M. tuberculosis colonies on Loeffler medium are small, dry, wrinkled, and off-white to yellow.
23Cornmeal 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.
24CHROMagar 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.
25Blood 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.
26Baird-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.
27BACTECThis 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.
28Sorbitol-MacConkey agarA variant of MacConkey agar, used in detecting E. coli O157:H7, which does not ferment sorbitol, unlike most strains of E. coli.
29Nutrient 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.
30Sauton’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.
31MacConkey 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.
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.
33Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
34Blood Agar (BA)E. coli colonies on this differential medium are large, circular, gray, moist, and can show β-hemolysis.
35Sf1Ep 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.
36Dorset 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.
37Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
38MacConkey Agar (MAC)This selective and differential medium distinguishes lactose fermenters from non-fermenters. E. coli colonies are circular, moist, smooth, and pink.
39Middlebrook 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.
40Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
41Enterococcosel 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.
42Todd-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.
43Blood 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.
1m-ENDO AgarE. coli colonies appear as green with a metallic sheen, indicating lactose fermentation.
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.
3Sabouraud 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.
4Potato 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.
5Tryptic 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.
6Mannitol 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.
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.
8Simmons 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.
9Violet Red Bile Agar (VRBA)E. coli colonies are red (pink to red) and may show bluish fluorescence under UV light.
10Petragnini 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.
11Cornmeal 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.
12Bile 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
13Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in this medium.
14Nickerson’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.
15Tarshis MediumA blood-based medium that can promote the growth of M. tuberculosis. The colonies appear similar to those on the LJ Medium.
16Dubos’ 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.
17Proskauer and Beck’s MediumA liquid medium. The growth of M. tuberculosis causes turbidity.
18Tryptic Soy Agar (TSA)A general purpose medium. E. coli colonies are medium to large, with a shiny moist appearance.
19Middlebrook 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.
20Azide 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.
21Loeffler MediumA serum-based medium. M. tuberculosis colonies on Loeffler medium are small, dry, wrinkled, and off-white to yellow.
22Brain-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.
23Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
24CHROMagar 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.
25Cystine Lactose Electrolyte-Deficient (CLED) AgarE. coli will give lactose-positive yellow colonies.
26Baird-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.
27BACTECThis 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.
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.
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.
31Sauton’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.
32MacConkey 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.
33Lysine 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.
34Lowenstein-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.
35Blood Agar (BA)E. coli colonies on this differential medium are large, circular, gray, moist, and can show β-hemolysis.
36Sf1Ep 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.
37Dorset 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.
38Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
39MacConkey Agar (MAC)This selective and differential medium distinguishes lactose fermenters from non-fermenters. E. coli colonies are circular, moist, smooth, and pink.
40Middlebrook 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.
41RPMI 1640 MediumIt is a rich medium that contains inorganic salts, glucose, amino acids, vitamins, and other nutrients that promote the growth of yeast cells.
42Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
43Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
44Enterococcosel 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.
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.
47Blood 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.
48Sula’s MediumA liquid medium containing glycerol, asparagine, and a variety of salts. The growth of M. tuberculosis results in turbidity.
1m-ENDO AgarE. coli colonies appear as green with a metallic sheen, indicating lactose fermentation.
2Tarshis MediumA blood-based medium that can promote the growth of M. tuberculosis. The colonies appear similar to those on the LJ Medium.
3Proskauer and Beck’s MediumA liquid medium. The growth of M. tuberculosis causes turbidity.
4Dubos’ 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.
5Tryptic Soy Agar (TSA)A general purpose medium. E. coli colonies are medium to large, with a shiny moist appearance.
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.
7DNase 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.
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.
9MacConkey 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.
10Lysine 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.
11Lowenstein-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.
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.
13Mueller Hinton Agar (MHA)Typically used for antibiotic susceptibility testing. E. coli colonies appear pale straw colored.
14MacConkey Agar (MAC)This selective and differential medium distinguishes lactose fermenters from non-fermenters. E. coli colonies are circular, moist, smooth, and pink.
15Middlebrook 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.
16Middlebrook 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.
17Pawlowsky MediumA potato-based medium. Growth of M. tuberculosis may be similar to that seen on the LJ Medium.
18RPMI 1640 MediumIt is a rich medium that contains inorganic salts, glucose, amino acids, vitamins, and other nutrients that promote the growth of yeast cells.
19Phenol 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.
20Violet Red Bile Agar (VRBA)E. coli colonies are red (pink to red) and may show bluish fluorescence under UV light.
21Simmons 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.
22Baird-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.
23BACTECThis 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.
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.
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.
26Petragnini 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.
27Cornmeal 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.
28Eosin Methylene Blue (EMB) AgarA selective and differential medium where E. coli forms distinctive metallic green sheen colonies due to vigorous lactose fermentation.
29Enterococcosel 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.
30Brilliant Green Agar (BGA)A selective medium that is used to isolate Salmonella species, but E. coli can grow on it, albeit not as well.
31Todd-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.
32Blood 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.
33Triple 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.
34Nutrient 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.
35Sorbitol-MacConkey agarA variant of MacConkey agar, used in detecting E. coli O157:H7, which does not ferment sorbitol, unlike most strains of E. coli.
36Tryptic 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.
37Mannitol 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.
38Loeffler MediumA serum-based medium. M. tuberculosis colonies on Loeffler medium are small, dry, wrinkled, and off-white to yellow.
39Azide 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.
40Nutrient Agar (NA)A non-selective medium. E. coli colonies are usually large, circular, grayish-white, moist, and smooth.
41Blood Agar (BA)E. coli colonies on this differential medium are large, circular, gray, moist, and can show β-hemolysis.
42Brain-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.
43Sula’s MediumA liquid medium containing glycerol, asparagine, and a variety of salts. The growth of M. tuberculosis results in turbidity.
44Urea Agar/BrothE. coli is typically urease negative, so no color change would be expected in this medium.
45Bile 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
46Nickerson’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.
47CHROMagar 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.
48Cystine Lactose Electrolyte-Deficient (CLED) AgarE. coli will give lactose-positive yellow colonies.
49Blood 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.