Lab 30: IMViC Series - MP-VP Test

Question 1

what is the purpose of Methyl Red and Voges-Prokauer test?

Answer 1

originally developed to distinguish between E. coli and E. aerogenes. helps differentiate between other members of the Gram-negative bacilli

Question 2

-MR-VP test detects?
-positive MR reaction indicates?
-positive VP reaction indicates?

Answer 2

-the byproducts of glucose metabolism
-a positive MR reaction indicates large quantities of acid were produced from catalysis of glucose
-a positive VP reaction indicates a neutral substance, such as acetoin, was the end product of glucose metabolism
-both utilize glucose

Question 3

what is MR VP broth?

Answer 3

nutrient broth with added glucose

Question 4

what reagents are used?

Answer 4

VP reagent A and B
methyl red pH indicator solution

Question 5

results

Answer 5

if MR is pos = VP neg and vice versa
-yellow/brown = neg MR or neg VP
-red = pos MR or pos VP