Clinical and Laboratory Standards Institute document MM06-A2—Quantitative Molecular Methods for Infectious Diseases; Approved Guideline—Second Edition recognizes the increased use of quantitative molecular methods for determining the concentration of microorganisms in patients. CLSI document MM06 provides guidance for the development and use of quantitative molecular methods, such as nucleic acid probes and nucleic acid amplification techniques of the target sequences specific to particular microorganisms, and presents recommendations for quality assurance, proficiency testing, and interpretation of results. Issues specific to the quantification of nucleic acid in diagnostic testing and monitoring, particularly in viral diseases, include an update on technologies used in molecular quantification; specimen handling and preparation; standards, calibrators, and reference materials; analytical and clinical verification/validation; reporting and interpreting results; clinical utility; and recommendations for manufacturers and clinical laboratories.

This document is an update of MM06—Quantitative Molecular Methods for Infectious Diseases; Approved Guideline that was published in 2003. MM06 established the original guidelines for laboratory tests that quantified viruses for the purpose of diagnosis and monitoring of infected patients. This guideline is to be used in conjunction with CLSI document MM03.1 This document constitutes the second edition of MM06 and specifically addresses the changes in technology, performance, assay verification, interpretation, and quality control (QC) for quantitative molecular methods in the diagnosis and monitoring of infectious diseases.

This guideline is to be used for implementation of tests for diagnostic purposes after the benefits and potential risks associated with the use of the test in clinical practice have been considered. Specimen handling and preparation; standards, calibrators, and reference materials; analytical and clinical verification/validation; reporting and interpreting results; and QC and clinical utility are the focus of this document. This document does not establish a clinically acceptable limit of quantification (LoQ) because consensus for most assays is currently lacking on this issue. This document is intended for manufacturers or laboratories that develop tests, laboratories that perform or intend to implement such tests, clinicians that use the results to diagnose or manage patients, and agencies that regulate their use.