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.

Tryptic Soya Agar is recommended for cultivation and maintenance of Salmonella Typhimurium.It supports the growth of wide variety of organisms including fastidious and non fastidious such as Salmonella, Neisseria, Listeria, Brucella etc. The medium with added dextrose (glucose), sodium chloride and agar is recommended for the cultivation of Salmonella Typhi.

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.

recommended as differential and selective medium for the isolation of Salmonella and Shigella species from pathological specimens and suspected foodstuffs and for microbial limit test. It is a moderately selective medium in which gram-positive bacteria are inhibited by bile salts, brilliant green and sodium citrate

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.

Selenite Cystine Broth Base w/o Biselenite is recommended as a selective enrichment media for Salmonella and possibly Shigella sonnei from faeces, urine, water and foodtuffs. It is useful for detecting Salmonella in the nonacute stages of illness when organisms occur in the faeces in low numbers and for epidemiological studies to enhance the detection of low number of organisms from asymptomatic or convalescent patients.

This medium is used as a selective enrichment medium for Salmonellae species from food, animal feeding stuffs, pharmaceutical products. This medium can also be used in direct enrichment of samples containing low inoculum

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.