CRM002 Chromogenic E.coli Agar





For the rapid detection and enumeration of Escherichia 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 and large intestine coli β- glucuronidase enzyme specific reaction, hydrolysis of the substrate, the release of the color groups produce green colonies on the light yellow plate.

Formulation (per liter):

Peptone :15.0g

Yeast extract powder: 3.0g

Sodium chloride: 5.0g

Sodium lauryl sulfate:0.1g

Agar: 12.0g

Chromogenic substrate 6.5g

Final pH 7.0 ± 0.2

How to use:

1. Weigh 41.6g of the product, adding 1.0L distilled or deionized water, heated to boiling stirring until completely dissolved, dispensing into flask, 115 autoclaved for 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 the 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            green colonies

Citrobacter              ATCC8090           good           colorless 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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