Dehydration or moisture loss during transit.
CLSI M22-A3 is the third edition of a Clinical and Laboratory Standards Institute (CLSI) guideline titled "Methods for Antimicrobial Disk Susceptibility Tests" (note: CLSI document codes sometimes vary; M22 series specifically covers antimicrobial susceptibility testing methods and interpretive criteria). This edition updates procedures, quality-control recommendations, and interpretive criteria for disk diffusion testing of bacteria to ensure reliable, reproducible susceptibility results across clinical microbiology laboratories.
Examine every shipment upon receipt for physical defects, including cracked plates, hemolysis, dehydration, freezing damage, bubbles, or contamination.
There is publicly available. The series appears to have been superseded by the broader CLIA regulatory changes and the introduction of the IQCP framework. The third edition remains the final and most comprehensive version of this standard. clsi m22a3 pdf
Here is a breakdown of legitimate and legitimate-but-wary options, and what to avoid.
Evaluate physical characteristics, including pH, fill volume, sterility, and gel strength.
Perform comprehensive QC testing on every batch/lot of media. Dehydration or moisture loss during transit
Media with a documented failure rate of are categorized as Exempt , meaning clinical laboratories are not required to perform their own routine QC testing on these products, provided certain conditions are met. Conversely, media with a failure rate greater than 0.5% are designated as Nonexempt , and user quality control is required.
When searching for the , the safest and most reliable approach is to purchase it directly from the CLSI website , the ANSI Webstore , or another authorized standards distributor. While a free, full-length version does not exist legitimately, the official sample PDF is an excellent starting point for evaluating the document's content before making a purchase. The legacy of M22-A3 endures as a testament to the power of consensus-based standard-setting in advancing the quality and efficiency of clinical laboratory medicine.
By implementing the guidelines within the standard, laboratories can justify reducing their QC workload. Instead of testing every single batch of standard agar plates, they can rely on the manufacturer's certificate, provided they maintain flawless records of inventory checks and storage temperature logs. Why Professionals Search for the CLSI M22-A3 PDF Examine every shipment upon receipt for physical defects,
The CLSI M22A3 PDF document provides detailed information on the performance and interpretation of antimicrobial susceptibility tests, including:
Are you looking to update your for media receipt? Share public link
Are you setting up a or updating an existing one?
The CLSI M22-A3 (3rd Edition) document, "Quality Control for Commercially Prepared Microbiological Culture Media," provides guidelines for the QC testing of microbiological culture media, focusing on reducing testing for low-failure "exempt" media. It classifies media into exempt and non-exempt categories, detailing specific QC parameters and the division of responsibility between manufacturers and clinical laboratories. The standard is a copyrighted publication of the Clinical and Laboratory Standards Institute (CLSI) and can be purchased on their official website or accessed through institutional subscriptions.
: M22-A3 is currently considered an archived standard by CLSI. Many laboratories now transition to using an Individualized Quality Control Plan (IQCP) as outlined by CMS to manage their media QC.