MRVP Agar (Dehydrated), Differentiate coli-aerogenes group by Methyl-red and Voges-Proskauer test with this glucose phosphate medium, Each

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Differentiate coli-aerogenes group by Methyl-red and Voges-Proskauer tests with Thermo Scientific™ Oxoid™ MRVP Agar (Dehydrated). This glucose-phosphate medium is recommended for the Methyl-red and Voges-Proskauer tests, for the differentiation of the coli-aerogenes group1. Both of these tests are based on the detection of specific breakdown products of carbohydrate metabolism.Use MRVP Agar for differentiation of coli-aerogenes group by the Methyl-red and Voges-Proskauer test.Smith2 noted the low acid production of Enterobacter aerogenes cultures as compared with those of Escherichia coli. Clark & Lubs3 employed methyl-red as a hydrogen-ion concentration indicator in order to differentiate glucose phosphate peptone water cultures of members of the coli-typhoid group. This test, now known as the Methyl-red test, distinguishes those organisms able to form large amounts of acid from glucose so that the pH falls below 4.4 and those organisms which cannot produce a low pH level.The difference in pH value is visualised by adding methyl-red to the culture, (pH 6.0 yellow).Voges & Proskauer4 described a red fluorescent coloration that appeared after the addition of potassium hydroxide to cultures of certain organisms in glucose medium. The coloration was shown to be due to the oxidation of the acetylmethyl-carbinol producing diacetyl which reacts with the peptone of the medium to give a red colour5,6. Durham7 noted that Enterobacter aerogenes gave a positive reaction but that Escherichia coli produced no coloration, and it later became clear that there was a negative correlation between the Methyl-red and Voges-Proskauer tests8,9 for lactose-fermenting coliform organisms.Not all products are available for sale in all territories. Please inquire.Remel™ and Oxoid™ products are now part of the Thermo Scientific brand.