CLSI

CLSI (Clinical and Laboratory Standards Institute) is a United States–based, not-for-profit organization that develops voluntary consensus standards and guidelines for clinical laboratory testing. Its standards cover a broad range of laboratory disciplines, with a focus on ensuring the accuracy, reliability, and timeliness of patient test results. CLSI’s work informs routine laboratory operations, quality management, method validation, and performance testing, including antimicrobial susceptibility testing.

CLSI originated in the 1960s as the National Committee for Clinical Laboratory Standards (NCCLS) and adopted the CLSI name in 2005 to reflect its international participation. The organization is governed by a board of directors and a network of technical committees, with engagement from laboratories, manufacturers, clinicians, and academic partners. CLSI operates globally through member organizations and collaborations that help disseminate standards and guidance.

Publications and guidance: CLSI publishes standards and guidelines in a series of documents that laboratories use to evaluate and implement testing methods, establish quality control procedures, and validate new technologies. The documents are developed through a consensus process with input from experts across industry, healthcare, and research communities.

Impact and access: CLSI standards are widely adopted by clinical laboratories and referenced by accreditation and regulatory bodies, as well as by diagnostic manufacturers. Standards are typically distributed in printed or electronic formats; CLSI also offers education, workshops, and related resources to support implementation of its guidance.