How many tests are included in the IMViC series?

The IMViC series consists of four distinct tests: Indole, Methyl Red, Voges-Proskauer, and Citrate utilization. These biochemical tests are commonly used to differentiate members of the family Enterobacteriaceae, particularly in the identification of Escherichia coli and Enterobacter aerogenes. Each test assesses different metabolic capabilities of the bacteria, providing valuable information that aids in microbial identification.

For example, the Indole test checks for the production of indole from tryptophan, while the Methyl Red test assesses acid production from glucose fermentation. The Voges-Proskauer test looks for the presence of acetoin, and the Citrate test evaluates the ability of organisms to utilize citrate as a sole carbon source. The combination of all four tests gives a comprehensive view of the biochemical characteristics of the organism being studied, making the correct answer four.