California mastitis test

The California mastitis test (CMT) is a simple cow-side indicator of the somatic cell count of milk.

A refined version of the test, which enhanced its sensitivity, and eliminated the confounding effect of milk fat, uses an anionic surfactant, which forms a gel with the DNA in somatic cells in the milk.

An equal volume of test reagent is added, and gently agitated.

[4] A special reagent for the test is marketed under the name 'CMT-Test', but domestic detergents are frequently used instead, being cheaper and more readily available.

Fairy Liquid is as suitable as a reagent for the CMT, although many cheaper detergents are not.