The document can be purchased directly from the Clinical and Laboratory Standards Institute official website (clsi.org) in both electronic (PDF) and print formats.

Non-Exempt media are complex, highly selective, or nutrient-labile formulations that are prone to degradation during transport, storage, or preparation.

A single proficiency testing failure traced to media defects (undetected due to lack of proper QC) can destroy a lab’s reputation and lead to license revocation.