California Mastitis Test

The California Mastitis Test (CMT) is a simple, low-cost, cow-side diagnostic test used to estimate the somatic cell count of milk as an indicator of mastitis in dairy cattle. The test works by mixing a milk sample with a reagent that disrupts the cell membranes of any somatic cells present, releasing their DNA to react with the reagent and form a visible gel, with a stronger gel reaction indicating a higher somatic cell count. Because it can be performed immediately in the milking parlor, the CMT is a useful technique for detecting subclinical cases of mastitis, before the disease becomes clinically obvious.