CLSI M22-A3 standard, titled "Quality Control for Commercially Prepared Microbiological Culture Media," is a critical document for ensuring the reliability of laboratory results through standardized media testing. Released in June 2004, this third edition provides a framework for both manufacturers and end-user laboratories to manage the quality of ready-to-use culture media. Clinical & Laboratory Standards Institute | CLSI Core Purpose and Scope
Physical Integrity: Checking for correct pH, moisture levels, color, and lack of hemolysis (for blood-based media). Why the PDF Version is Essential clsi m22a3 pdf
Visual Inspection Criteria: Even for exempt media, labs must check for physical defects such as: Cracked Petri dishes or tubes. Excessive bubbles or rough surfaces. Obvious contamination or hemolysis. Incorrect agar depth (less than 3 mm) or unequal filling. Online SPE and automation are becoming standard
A: Yes. The standard requires lot-level testing per manufacturer. Different manufacturers may use different formulations or production processes, so performance can vary. Physical Integrity : Checking for correct pH, moisture
Clarified Responsibilities: It explicitly defines the roles of the manufacturer, distributor, and end-user laboratory.
: It includes new recommendations for the quality control of media used to grow "fastidious" (difficult to grow) organisms. Clinical & Laboratory Standards Institute | CLSI Why This Matters for Laboratories
CLSI M22-A3 document, titled "Quality Control for Commercially Prepared Microbiological Culture Media; Approved Standard—Third Edition,"