Barritt Reagent B is used in Voges-Proskauer test for detection of acetoin production by bacterial culture.VP test is helpful in identifying members of the family Enterobacteriaceae. Biochemical identification was carried out by adding 0.6 ml of Barritt Reagent (Part A)(R029) and 0.2 ml of Barritt Reagent (Part B) (R030) in 24-48 hours old cultures grown in MR-VP Medium (M070).Enterobacter aerogenes ATCC 13048 Positive (Cherry red colour formation); Escherichia coli ATCC 25922 Negative (No red colour formation)