M22-A3 introduced several significant changes from the previous M22-A2 version based on extensive surveys by the :
Quality Control for Commercially Prepared Microbiological Culture Media
Focus on visual inspection and documentation of media upon receipt rather than full organism-based retesting for "exempt" media. clsi m22a3 pdf
Excessive moisture, dehydration, or frozen/melted agar. Contamination: Any visible growth or excessive bubbles. Purchasing and Access
While certain media are exempt from full retesting, labs must still perform a for physical defects upon receipt of every shipment. The standard requires monitoring for: Purchasing and Access While certain media are exempt
The acceptable failure rate cutoff for exempting media was increased from 0.3% to 0.5% .
Use the standard to establish rigorous QC protocols for every lot. The full document is available in electronic PDF
The full document is available in electronic PDF format from various official standards retailers. Go to product viewer dialog for this item. CLSI M22-A3 (R2018)
It explicitly defines the roles of the manufacturer, distributor, and end-user laboratory.
The standard, titled "Quality Control for Commercially Prepared Microbiological Culture Media; Approved Standard—Third Edition," provides a framework for both manufacturers and laboratory users to ensure the reliability of ready-to-use culture media. Published in 2004, it serves as a consensus-based guide for maintaining quality assurance in clinical microbiology. Key Purpose and Scope