Under CLIA regulations, laboratories must perform quality control on all culture media. However, CLIA allows laboratories to follow CLSI M22-A3 guidelines to reduce the frequency of testing for commercially prepared exempt media. If a laboratory chooses not to follow M22-A3, it must perform full QC testing on every lot of every medium type used, creating a massive operational and financial burden. Summary of Benefits
In clinical and industrial microbiology laboratories, the reliability of test results depends heavily on the quality of the media used to grow and identify microorganisms. The Clinical and Laboratory Standards Institute (CLSI) provides comprehensive guidelines to ensure this quality. One of the cornerstone documents in this field is the , titled "Quality Control for Commercially Prepared Microbiological Culture Media; Approved Standard—Third Edition."
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Always cross-reference CLSI M22-A3 with your local regulatory frameworks (e.g., IQCP under CLIA) to ensure comprehensive compliance.
The standard identifies specific, reliable media that do not require user-side retesting (QC testing) if manufacturer certification is provided and verified upon receipt.
Antimicrobial disks and potency
Reporting and clinical implications
Furthermore, M22-A3 aligns with the , which applies a core set of "Quality System Essentials" (QSEs) to all operations in a healthcare service's path of workflow.
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Without adherence to M22-A3, a laboratory cannot scientifically prove that its culture media performed as expected on any given test day.
If a laboratory prepares its own media from dehydrated powder, M22-A3 mandates that all such media be treated as non-exempt, requiring full performance and sterility testing for every batch. Selecting ATCC Control Strains for Quality Control