The IMViC tests are useful for differentiating the Enterobacteriaceae, especially when used alongside the urease test. When used alone, the IMViC tests are particularly useful for differentiating Escherichia coli, Enterobacter aerogenes, Enterobacter cloacae, and Klebsiella pneumoniae (although colonial morphology and the presence of capsules can also be used to differentiate Klebsiella).
The IMViC series includes four tests:
Indole production (for which we use SIM medium)
the methyl red test
the Voges-Proskauer test
and citrate production
Except for the lowercase "i", which is added for ease of pronunciation, each of the letters in "IMViC" stands for one of these tests. "I" is for indole; "M" is for methyl red; "V" is for Voges-Proskauer, and "C" is for citrate.