Clsi M22a3 Pdf ((link)) Jun 2026

For laboratory professionals, pathologists, and manufacturers seeking the , understanding the core tenets of this standard is vital for maintaining compliance, reducing unnecessary laboratory costs, and ensuring patient safety. What is CLSI M22-A3?

Contact your biological supply company (e.g., Microbiologics, Thermo Fisher, ATCC) and ensure you have all the recommended strains. Prepare a working stock system with proper viability controls.

These are media formulations that have demonstrated an exceptionally low failure rate (typically less than 0.1%) during manufacturing and transit. Examples include standard MacConkey agar, Nutrient agar, and Sabouraud Dextrose agar. Laboratories are not required to perform routine maintenance QC (such as sterility or performance testing with control organisms) on these media, provided the manufacturer is ISO-certified and provides a certificate of analysis.

Summary

The standard explicitly applies to , ready-to-use microbiological culture media. It does not cover media prepared entirely in-house from raw ingredients (though those labs may still use it as a reference). Intended users include clinical labs, public health labs, veterinary diagnostics, and industrial microbiology facilities. clsi m22a3 pdf

, which significantly reduces the workload for microbiology laboratories. By classifying certain commercially prepared media as exempt, the standard removes the requirement for end-users to perform redundant quality control (QC) retesting on media with proven reliability. Clinical & Laboratory Standards Institute | CLSI Key Features of CLSI M22-A3 Expansion of Exempt Media

During an audit, inspectors frequently ask to see the scientific rationale behind a laboratory's media exemption list. Referencing the specific tables within the M22-A3 PDF provides instant justification.

Is your laboratory currently seeking or maintaining ?

Many labs validate in neat solvent (e.g., methanol/water) but not in biological matrix (serum, urine, plasma). M22-A3 is explicit: validation must occur in the biological matrix of interest. Failure to do this invalidates your LLOQ and recovery numbers. Prepare a working stock system with proper viability

The CLSI M22-A3 standard applies to , regardless of packaging, plate, or tube design. The media types included in the M22 standard are well-established for the recovery of clinically significant microorganisms.

Many hospital networks, university libraries, and reference laboratories maintain a site-wide subscription to the CLSI eCLIPSE database, granting all staff members access to the current PDFs. Conclusion

To better understand how this standard applies to your current facility, tell me:

Maintain a certified Quality Management System (QMS), such as ISO 13485. Laboratories are not required to perform routine maintenance

Test each lot for sterility, growth performance, and selectivity using specific control strains.

When executing a quality control protocol based on the M22-A3 standard, laboratories must monitor several key characteristics: 1. Physical Characteristics (Visual Inspection)

Before the widespread adoption of M22-A3, clinical labs varied wildly in how they validated HPLC (High-Performance Liquid Chromatography) and UPLC (Ultra-Performance Liquid Chromatography) methods. M22-A3 standardizes:

The Clinical and Laboratory Standards Institute (CLSI) is a global, not-for-profit, membership-driven organization dedicated to developing clinical laboratory standards that promote excellence in laboratory medicine. CLSI M22-A3 is an approved standard that contains quality assurance procedures for manufacturers and users of prepared, ready-to-use microbiological culture media.

Document that the media was stored at the manufacturer-specified temperatures continuously.