Guidelines for using positive and negative control organisms to confirm the medium's efficacy. Where to Find the CLSI M22-A3 PDF
In clinical microbiology, the accuracy of diagnostic results depends heavily on the quality of culture media. To ensure consistency and reliability, laboratories and manufacturers follow strict quality control (QC) guidelines. The definitive standard for this process is the Clinical and Laboratory Standards Institute (CLSI) document , titled "Quality Control for Commercially Prepared Microbiological Culture Media."
Testing growth-supporting characteristics with specific control organisms. clsi m22a3 pdf link
Significant changes introduced in the M22A3 document include:
One of the most influential aspects of M22-A3 is its definition of . The standard argues that for certain media with a proven track record of reliability, user-performed quality control (QC) is unnecessary. This is based on: Guidelines for using positive and negative control organisms
Categorize incoming media based on standard lists. 3. Exempt vs. Non-Exempt Media
: Provides a preview of M22-A3 for free, which includes the table of contents and scope. The full version can be purchased on the ANSI CLSI M22-A3 page . The definitive standard for this process is the
For non-exempt media, laboratories must maintain a collection of American Type Culture Collection (ATCC) strains. The standard outlines:
For professionals seeking the , the document establishes standardized, streamlined protocols for ensuring the performance of commercially prepared culture media, balancing stringent quality assurance with practical laboratory efficiency. You can access the official electronic publication directly via the CLSI M22 Product Page .
: The document simplified basic protocols for maintaining quality control organisms and updated incubation conditions. Clinical & Laboratory Standards Institute | CLSI Why Standards Like M22-A3 Matter
If an exempt or non-exempt medium fails visual inspection or growth performance, document the failure and report it to the manufacturer immediately.