Agar McConkey recommend selective isolation of enterobacteria and gramnegative sticks close to them.

Agar MacConkey Ingredient g / l

Peptone from casein 17.00

Peptone of meat 3.00

Bile acids 1.50

Sodium Chloride 5.00

Lactose 10.00

Neutral red 0.03

Crystal wreath 0,001

Agar 15.00

How to cook MacConkey agar:

51.53 g of dry medium dissolve in 900 ml of distilled water. Boil the mixture until the ingredients are completely dissolved, check pH and, if necessary, adjust the value to 7.1 ± 0.2, using a 10% solution of NaOH or a 10% solution of HCl. Bring the volume to 1000 ml and sterilize in an autoclave at 121 ° C for 15 minutes. Density of the prepared medium: The medium corresponding to the density of 1.35% agar gel is formed.

Color and transparency of the finished medium: The finished medium has a red color, slightly opalescent, if in Petri dishes, then gel forms.

Principle and evaluation of the result: It is recommended for isolation of enterobacteria from pathological materials, from water, foodstuffs.

This medium is used to differentiate some groups of gram-negative bacteria.

The selective action of this medium is due to bile salts which suppress most gram-positive bacteria. Gram-negative bacteria grow well on the medium and distinguish them due to the ability to ferment lactose.

After inoculation of the medium by the test sample, place it in the incubator for 18-24 hours at a temperature of 35-37 ° C.

Results:

Microorganism Streams (ATCC) Growth

Enterobacter aerogenes abundant

Proteus vulgaris abundant

Shigella flexneri is kind

Enterococcus faecalis is good

Acidity of the medium: At 25 ° C, aqueous solution (5.0% w / v) pH 7,1 ± 0,2.

Packaging: Plastic pot 500 gr