Microbiology Test
Microbiology Test

Tri-color Agar Medium

Tri-color Agar Medium

Coliforms and E. coli simultaneous detection (Sodium lauryl sulfate);

Desoxycholate Lactose Agar replaces the deoxycholate agar medium to be the new generation medium and is included in the “Food Hygiene Inspection Guide” [Appendix II] prepared by the Japanese Ministry of Health, Labor and Welfare.


Colonies Coloring:

E. coli colonies appear purple to blue-purple;

Coliforms colonies appear red to red-purple;

Other intestinal bacteria are white.


Functional Applications <Food / Water / Milk / Ice Cream / Meat Products>

It is widely used in the simultaneous qualitative and quantitative detection of coliforms, Escherichia coli and other intestinal bacteria in food, water, milk, ice cream, and meat products.


Usage Method of Tri-color Agar Medium

Add 7.85g (1bag) of powder medium into 200ml of pure water, dissolve by heating or autoclaving, mix the medium with the sample below 50 ° C to mixed culture; or pour into the culture dish, the sample was uniformly coated on the surface of the plate on which the medium had solidified, smeared and cultured at 35-37 ° C for 18-24 hours. Since about 95% of E. coli contains β-glucuronidase, it hydrolyzes the reaction substrate X-GLUC, and the hydrolyzates appear blue to light purple. The coliforms produce β-galactosidase, which catalyzes the hydrolysis of Magenta-GAL, and the hydrolyzates appear red to purple. Other Gram-positive bacteria are inhibited. The product cannot be used to identify E.coli 0157 separately.


Performance Characteristics of Tri-color Agar Medium

Three colors / simultaneous detection / quantitative counting

1. The medium contains two chromogenic substances, which can directly recognize coliforms and E. coli without adding any reagents.

2. It is easy to use, no need to mix medium, and the sensitivity of colony color change is completely suitable for food microbial inspection and easy to count.

3. SDS (sodium lauryl sulfate) in the medium inhibits Gram-positive bacteria and yeast.


Product Details of Tri-color Agar Medium

Product NameModelPackingValidity Period
Tri-color mediumXMA-01Packing: 7.85g/bag X 40bags/box3 years


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