Clinical and Laboratory Standards Institute document M50-A—Quality Control for Commercial Microbial Identification Systems; Approved Guideline includes a process for streamlined quality control (QC) of commercial microbial identification systems (MISs) that utilize multiple substrates and/or reagents to identify aerobic or anaerobic bacteria, yeasts, moulds, or yeast-like algae from culture. It specifies responsibilities of the manufacturer, distributor, and user. M50-A includes guidelines that may be followed when using an MIS of proven reliability to take a modified QC approach, rather than meeting requirements included in the Clinical Laboratory Improvement Amendments of 1988 regulations. The streamlined QC approach was developed following an evaluation of data provided by the American Society for Microbiology for a survey conducted to determine the QC failure rates of commercial MISs. The data showed a failure rate of less than 0.1% for all commercial MISs surveyed. This document is based on United States (US) regulations and will also serve as a useful resource for a wider audience. It is anticipated that M50-A will be used extensively in the United States and internationally to reduce resources spent on excessive QC testing.

This document provides quality control (QC) information for commercially available microbial identification systems (MISs), which are test systems that utilize multiple substrates and/or reagents to identify aerobic or anaerobic bacteria, yeasts, moulds, or yeast-like algae (eg, Prototheca species) grown from culture. It does not address primary isolation media, chromogenic agars, direct antigen tests, stains, or molecular methodologies used for microbial identification; nor does it address QC of antimicrobial susceptibility tests. The document specifies the QC responsibilities of the manufacturer, distributor, and user, and identifies conditions under which an MIS with proven reliability can qualify for streamlined QC testing. The modified approach may be applied after the user verifies acceptable MIS performance as specified in this guideline. Implementation of streamlined QC testing by users assumes that the MIS performance is monitored by overall quality assurance (QA) programs on the part of the manufacturer, distributor, and user. This document is based on United States (US) regulations and will also serve as a useful resource for a wider audience. It is anticipated that M50-A will be used extensively in the United States and internationally to reduce resources spent on excessive QC testing.