This guideline replaces the previous edition of the approved guideline, MM13-A, published in 2005. Several changes were made in this edition, including: • Providing pertinent information on specimen types in the text instead of in tables • Adding subchapters on enrichment • Adding a subchapter on evaluating purified nucleic acids (postextraction) • Revising and updating subchapters on tissue preparation and cell-free DNA isolation and purification

This guideline describes general technical principles for ensuring optimal specimen collection, transport, storage, and nucleic acid isolation for molecular diagnostic test methods. It is intended for all health care professionals responsible for obtaining and transporting specimens from patients or preparing samples for molecular tests. It is also intended for manufacturers of specimen collection devices and sample preparation reagents, kits, and instrumentation. This guideline also describes specimen collection and transport devices, sample preparation methods and optimal storage conditions, and special precautions for molecular methods. Although this guideline is intended for diagnostic testing, the principles described here may apply to other areas. MM13 also discusses QMS principles that should be implemented to meet regulatory and accreditation requirements. CLSI documents QMS01(1) and MM19(2) also provide thorough QMS implementation guidance. For guidelines and best practices covering specimen collection, transport, handling, and storage safety, refer to CLSI document GP17(3) and other available resources (eg, regulatory agencies,4 World Health Organization). International guidance is also available.5 For specimen handling information unique to specific technologies or subspecialties, consult CLSI documents MM03,(6) MM05,(7) MM09,(8) and I/LA28.(9)