Somatic cell count

A somatic cell count (SCC) is a cell count of somatic cells in a fluid specimen, usually milk. In dairying, the SCC is an indicator of the quality of milk—specifically, its low likeliness to contain harmful bacteria, and thus its high food safety. White blood cells (leukocytes) constitute the majority of somatic cells in question. The number of somatic cells increases in response to pathogenic bacteria like Staphylococcus aureus, a cause of mastitis. The SCC is quantified as cells per milliliter. General agreement rests on a reference range of less than 100,000 cells/mL for uninfected cows and greater than 250,000 for cows infected with significant pathogen levels. Several tests like the PortaSCC milk test and The California mastitis test provide a cow-side measure of somatic cell count. The somatic cell count in the milk also increases after calving when colostrum is produced.