Chromogenic Media

Usages:
For the rapid detection and of coliforms and E. coli.
 
Principle:
Peptone and yeast extract powder provides carbon and nitrogen sources and traces elements; sodium chloride maintains osmotic equilibrium; agar as medium coagulant; dodecyl sulfate inhibits Gram-positive bacteria; chromogenic substrate was mixed occurrence of coliforms and E. coli enzyme corresponding specific reactions, hydrolysis of the substrate, the release of the colour groups, in a pale yellow plates coliforms appears orange-red colonies while E.coli appears blue-green colonies.

Packaging size:
1000ml
 
Formulation (per litre):
Peptone 15.0g
Yeast extract powder 3.0g
Sodium chloride: 5.0g
Sodium lauryl sulfate: 0.1g
Agar: 12.0g
Mixed chromogenic substrate: 6.77g
Final pH 7.0 ± 0.2
 
How to use:

1. Suspend 41.9g of the product, adding, 1.0 L of distilled or deionized water, heated to boiling stir until completely dissolved, dispensing into the flask, 115 ^oC autoclaved 10minutes.
2. Take 25.0g or 25.0mL of the sample with sterile procedures, added to the flask containing 225.0mL of sterile phosphate-buffered saline (or saline) , shaken thoroughly homogenized with a homogenizer or a 1:10 dilution of 1min solution, diluted 1:10 and then continue to select the appropriate serial dilutions of three, the two plates inoculated with each dilution, poured dissolved by heating and cooled to about 45 ^oC medium.
3. Observe the results.

 
Quality control:
This product appears light yellow after pouring on a plate, these strains were inoculated after 36 ± 1 ^oC 18 ~ 24h culture growth in the following table.

Bacteria name	Growth situation	Features
Escherichia coli (ATCC25922)	Good	Blue-green colonies
Citrobacter (ATCC8090)	Good	Orange-red colonies
Salmonella Typhimurium (CMCC50115)	Good	Colourless colonies
Enterococcus faecalis (ATCC29212)	Suppressed	-

 
Storage: Keep container tightly closed, store in a cool, dry place, away from bright light.
 
Specifications: Configurable 1L of Medium.