Culture media

This medium detects urease activity by all rapidly urease-positive Proteus organisms and also by other members of Enterobacteriaceae that exhibits a delayed urease reaction. Prolonged incubation may cause alkaline reaction in the medium. A medium without urea serves as negative control to rule out false positive results. Also, all urea test media rely on the alkalinity formation and so they are not specific for determining the absolute rate of urease activity. The utilization of proteins may raise the pH to alkalinity due to protein hydrolysis and excess of amino acids liberation results in false positive reaction.

Originally proposed by Sulkin and Willett and modified by Hajna for identifying Enterobacteriaceae . This medium complies with the recommendation of APHA, for the examination of meat and food products , for the examination of milk and dairy products and for microbial limit test for confirming the presence of Salmonellae and in the identification of gram-negative bacilli. The reactions can be interpreted as follows: Alkaline slant / acid butt- only glucose fermented, Acid slant / acid butt- dextrose and sucrose fermented or dextrose and lactose fermented or all the three sugars, dextrose,lactose and sucrose fermented, Bubbles or cracks present-gas production Black precipitate present-H2S gas production

This medium is highly recommended by APHA for the selective isolation of V. cholerae and V. parahaemolyticus. Enrichment in Alkaline Peptone Water (M618), followed by isolation on TCBS Agar is routinely used for isolation of V.cholerae.

Streptococcus Selection Agar is recommended for selective isolation and enumeration of all types of Streptococci, including group A beta haemolytic strains. Sodium azide, sodium sulphite inhibits gram-negative rods and the crystal violet suppresses Staphylococci. Growth of coliforms, Proteus, Pseudomonas and Bacillus species is markedly suppressed in this medium.

These media are used for the differentiation between Enterobacteriaceae and the members of aerogenes group on the basis of citrate utilization as sole carbon source by IMViC tests.

for determining plate counts of microorganisms in milk and dairy products by pour plate technique.it is also used for the estimation of the number of live heterotrophic bacteria in water.

This medium is used for maintaining microorganisms, cultivating fastidious organisms by enriching with serum or blood and are also used for purity checking prior to biochemical or serological testing.

MIU Medium Base is recommended for detection of motility, urease and indole production in single tube. Motility and urease reactions are read before testing Indole production. Motile organisms show either diffused growth or turbidity extending away from stab inoculation line while nonmotile organisms grow along the stabline. Organisms that utilize urea, produce ammonia which makes the medium alkaline, showing pink-red colour by change in the phenol red indicator. Indole is produced from tryptophan present in tryptone. The indole produced combines with the aldehyde present in the Kovac's reagent to form a red complex.

M-FC Agar Base is recommended for detection and enumeration of faecal coliforms using membrane filtration technique at higher temperature (44.5°C). This medium is based on the property of faecal coliforms to grow at 44-45°C.

This medium is recommended for the isolation of coagulase-positive staphylococci from cosmetics, milk, food and other specimens. The additional property of lipase activity of Staphylococcus aureus can be detected by the addition of the Egg Yolk Emulsion. The lipase activity can be visualized as yellow opaque zones around the colonies.

This granulated medium is used for presumptive identification of coliforms from variety of specimens such as water, milk and food etc. Bromocresol purple is the pH indicator in the medium which turns yellow under acidic condition, Colour of the medium chnages to yellow due to lactose fermentation and gas entrapped in Durhams tube.

This medium is used for the detection and isolation of gram-negative organisms from clinical , dairy, food, water, pharmaceutical and industrial sources. It is also recommended for the selection and recovery of the Enterobacteriaceae and related enteric gram-negative bacilli. USP recommends this medium for use in the performance of Microbial Limit Tests.

M17 Broth is recommended for cultivation of lactic Streptococci and their bacteriophages. It is usedfor the cultivation and enumeration of lactic Streptococci and their bacteriophages. This medium is a modification of M16 Medium.

Lactobacillus MRS Agar (MRS Agar)Recommended for the isolation and enumeration of lactic acid bacteria from meat and meat products. The composition and performance criteria of this medium are as per the specifications laid down in ISO 1995, Draft ISO/DIS 13720:2010. Peptone, HM Extract B, yeast extract , dextrose provides carbon and nitrogen sources for lactobacilli growth. Sodium acetate and ammonium citrate inhibit Streptococci, moulds and many other microorganisms. Magnesium sulphate and manganese sulphate provide essential ions for multiplication of lactobacilli. Phosphates provide good buffering action in the media. Polysorbate 80 supplies fatty acids required for the metabolism of Lactobacilli.