Gelatin Hydrolysis Test- Principle, Procedure, Types, Result, Uses


Gelatin hydrolysis test is a biochemical test that determines the ability of bacteria to produce gelatinase, an enzyme that breaks down gelatin. Gelatin is a protein derived from animal collagen, which forms a solid gel at low temperatures. Gelatinase hydrolyzes gelatin into smaller peptides and amino acids, which can be utilized by bacteria as a source of nutrients. Gelatin hydrolysis test is used as a presumptive test for the identification of various Gram-positive and Gram-negative bacteria, especially those that are involved in invasive infections. The test is based on the observation of the liquefaction of gelatin medium in the presence of gelatinase-producing bacteria. Alternatively, the test can also be performed by adding mercuric chloride to the gelatin medium, which precipitates gelatin and forms clear zones around the colonies of gelatinase-producing bacteria. Gelatin hydrolysis test is also known as gelatin liquefaction test or gelatinase test.