CRM003 E. coli and Coliform Chromogenic Agar





For the rapid detection and of coliforms and E. coli.


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

Formulation (per liter):

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. Weigh 41.9g of the product, adding , 1.0 L of distilled or deionized water, heated to boiling stir until completely dissolved, dispensing into flask, 115 autoclaved 10minutes.

2, Take 25.0g or 25.0mL of 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 medium.

3, observe the results.

Quality control:

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

Bacteria name            bacteria NO.       growth situation         feature

Escherichia coli          ATCC25922            good         blue-green colonies

Citrobacter              ATCC8090             good         orange-red colonies

Salmonella typhimurium   CMCC50115          good           colorless colonies

Enterococcus faecalis     ATCC29212           suppressed            —–

Storage: Store in a dark, cool and dry place, tighten the caps immediately after use. Storage period of two years.

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