Broth McConcie recommend selective isolation of enterobacteria and gramnegative sticks close to them.

Composition g / l

Peptone 20.00

Lactose 10.00

Bile salts 5,00

Sodium Chloride 5.00

Bromocresol purple 0.01

Appearance:

A bottle of 500 g of dry medium.

Method of cooking:

Mix 40,075 g of dry medium in 1000 ml of distilled water. The mixture is boiled to

complete dissolution of ingredients, check pH and, if necessary, adjust the value of 7.4 ± 0.2,

using 10% NaOH solution, or 10% solution. HCl.

Sterilize in an autoclave at 121 ° C for 15 minutes.

Color and transparency of the finished medium:

The finished medium has a red color, a slight precipitate, slightly opalescent.

Acidity of the medium:

At 25 ° C, an aqueous solution (4.00% w / v) pH 7.4 ± 0.2.

Principle and score of the result:

 Used for the isolation and identification of microorganisms in the E. coli group

water and food products.

 Peptone provides the environment with nitrogen and vitamins.

 Bile salts inhibit the development of microbial flora of gram-positive bacteria.

Bromocresol purple is an indicator of pH when acidified with the medium

place as a result of fermentation of lactose.

 After inoculation of the medium by the test sample, place it in the incubator on

18-24 hours at a temperature of 35-37 ° C.

Results:

Microorganism Streams (ATCC) Growth Acid Gas

Enterobacter aerogenes ATCC 13048 +++ + +

Escherichia coli ATCC 25922 +++ + +

S. Cholerasuis ATCC 12011 ++ - -

Staphylococcus aureus ATCC 25923 - - -