The methyl red and Voges-Proskauer tests are used to distinguish between members of the family Enterobacteriaceae, as well as to characterize other groups of bacteria, including Actinobacteria. Both the methyl red and Voges-Proskauer tests are commonly used in conjunction with the indole and citrate tests to form a group of tests known as IMViC, which aid in the differentiation of Enterobacteria.