Milk somatic cell count is a widely used indicator for monitoring the udder health of several mammalian species and is relevant in food hygiene regulations, milk payment testing, farm management and breeding programmes. In 2020, the EC Joint Research Centre launched new certified reference materials for somatic cell counting in milk.
This paper provides relevant guidance on how to apply this material for method performance verification of both the microscopic reference method and routine methods, for verification and possibly required adjustment of calibration settings of routine methods, for assigning reference values to secondary reference materials and for use in proficiency testing.
Application of this new certified reference material for calibration of routine methods might come with a significant change in calibration settings. In such cases, it is advised that laboratories consult the relevant regulatory and supervising bodies and other local stakeholders in order to arrange for an optimal transition.