YEPD Agar- Composition, Principle, Preparation, Results, Uses

Yeast Extract Peptone Dextrose (YPD or YEPD) Agar

Yeasts are unicellular eukaryotes and extensively studied model organism in molecular genetics. They are chemoorganotrophs as they utilize organic compounds as a source of energy. Yeast extract peptone dextrose (YPD or YEPD) Growth Agar is used for the maintenance and propagation of yeasts including S. cerevisiae in various molecular microbiology procedures. YPD functions as a complete medium for yeast growth. Composition of YEPD Agar Ingredients Gms/liter Peptone 20.000 Yeast extract 10.000 Dextrose 20.000 Agar 15.000 Final pH (at 25°C): 6.5±0.2 … Read more

Mueller Hinton Agar (MHA)- Composition, Principle, Preparation, Results, Uses

Result on Mueller Hinton Agar (MHA)

What is Mueller Hinton Agar (MHA)? Mueller and Hinton developed Mueller Hinton Agar (MHA) in 1941 for the isolation of pathogenic Neisseria species. Mueller Hinton agar is a microbiological growth medium that is commonly used for antibiotic susceptibility testing using the Kirby-Bauer disc diffusion method. MHA is recommended for the diffusion of antimicrobial agents impregnated on paper disc through an agar gel as described in CLSI Approved Standard. Zone diameters established for each antimicrobial determining resistant, intermediate, and sensitive results for pathogenic microorganisms are listed in the Clinical and … Read more

Peptone Yeast Extract Glucose Broth

Peptone Yeast Extract Glucose Broth

Peptone Yeast Extract Broth Based Media are enriched nonselective media that are supplemented with hemin and vitamin K to facilitate the recovery of the more fastidious organisms such as Prevotella spp, Porphyromonas spp, and the Bacteroides fragilis group. With the addition of a specific biochemical, the Peptone Yeast Extract Broth Based Media are used to determine whether anaerobic bacteria will utilize the biochemical or if growth is stimulated or inhibited. Peptone Yeast Extract Glucose Broth is a nonselective broth media originally formulated … Read more

BCYE Agar- Composition, Principle, Preparation, Results, Uses

Buffered Charcoal Yeast Extract (BCYE)

Feeley et al in 1978 developed a medium to isolate Legionella species which was later modified by substituting yeast extract for casein hydrolysate and beef extract, and replacing starch with activated charcoal and named it as Charcoal Yeast Extract (CYE) Agar. A further modification was made by Pasculle et al in 1980 by the addition of ACES (N-2-acetamido-2-aminoethane sulfonic acid) buffer in order to maintain the proper pH for optimal growth designated as BCYE for Buffered Charcoal Yeast Extract. In 1981, … Read more

Levinthal’s Medium- Composition, Principle, Preparation, Results, Uses

Levinthal’s Medium

Levinthal’s Medium is used for the cultivation of Haemophilus species. The genus Haemophilus includes a number of species that cause a wide variety of infections but share a common morphology and a requirement for blood-derived factors during growth that has given the genus its name. The Haemophilus genus represents a large group of gram-negative rods that grow on agar-containing blood. The blood provides two factors, which many Haemophilus species require for growth: factor-X and factor-V. Composition of Levinthal’s Medium Ingredients … Read more

EMB Agar- Composition, Principle, Preparation, Results, Uses

Eosin Methylene Blue (EMB) Agar

Eosin Methylene Blue (EMB) agar is a differential microbiological medium, which slightly inhibits the growth of Gram-positive bacteria and provides a color indicator distinguishing between organisms that ferment lactose (e.g.,  E. coli) and those that do not (e.g., Salmonella, Shigella). EMB agar was originally devised by Holt-Harris and Teague and further modified by Levine. It is thus a combination of the Levine and Holt-Harris and Teague formulae which contains a peptic digest of animal tissue and phosphate as recommended by Levine and two carbohydrates as suggested by … Read more

Alkaline Peptone Water- Composition, Principle, Preparation, Results, Uses

Alkaline Peptone Water

Alkaline Peptone Water is a broth medium for the enrichment of Vibrio species from food, water, and clinical samples. Shread, et al. formulated peptone water for use as a nonselective enrichment broth for the cultivation of Enterobacteriaceae from foodstuffs and other specimens. It is a modification of peptone water with the pH adjusted to 8.4. The alkaline pH of this medium allows the growth of Vibrio organisms while inhibiting the growth of commensal intestinal bacteria. Enrichment of specimens in Alkaline Peptone … Read more

Columbia Agar with 5% Sheep Blood- Composition, Principle, Preparation, Results, Uses

Columbia Agar with 5% Sheep Blood

Columbia Agar with 5% Sheep blood is a highly nutritious general-purpose medium for the isolation and cultivation of the non-fastidious and fastidious microorganisms from various clinical specimens and non-clinical specimens of public health importance.  Columbia Blood Agar was first described in 1966 by Ellner et al who incorporated animal-derived peptone, enzymatic digests of casein, and enriched medium by addition of the defibrinated sheep blood into one medium. It was found to be an improved blood agar, promoting both luxuriant and rapid … Read more

Martin Lewis Agar- Composition, Principle, Preparation, Results, Uses

Martin Lewis Agar

Thayer-Martin Agar was developed in 1964 for the isolation of N. gonorrhoeae and N. meningitidis. A further modification of these early formulations was developed to improve the isolation of pathogenic Neisseria sp. from specimens, which contained large amounts of mixed microbial flora. Martin-Lewis Agar is the formulation made after modification that contains an increased level of vancomycin for greater inhibition of gram-positive organisms. The development of the Martin-Lewis (ML) medium represents a more recent modification in the original Thayer-Martin formulation … Read more

Lysine Iron Agar (LIA)- Composition, Principle, Preparation, Results, Uses

Lysine Iron Agar (LIA)

Lysine iron agar (LIA) is a differential medium used to test organisms for the ability to deaminate lysine or decarboxylate lysine.  Lysine deamination is an aerobic process that occurs on the slant of the media. Lysine decarboxylation is an anaerobic process that occurs in the butt of the media. Edwards and Fife designed LIA in 1961 to presumptively identify Salmonella species, including lactose fermenting Salmonella arizonae, which has been implicated in foodborne outbreaks of gastroenteritis. Composition of Lysine Iron Agar (LIA) Ingredients Gms/liter Peptone 5.000 Yeast extract 3.000 Dextrose (Glucose) 1.000 L-Lysine 10.00 Ferric … Read more