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CLSI: Clinical And Laboratory Standards Institute

CLSI, the Clinical and Laboratory Standards Institute, is a nonprofit organization that develops and publishes standards serving the health care industry. Headquartered near Philadelphia, United States, CLSI standards, through the over 2,000 organizations and 2,000 individuals in the CLSI membership base, have greatly influenced the current state of its field on an international level. CLSI is the secretariat of ISO/TC 212 (International Organization for Standardization/Technical Committee), as well as serving as the administrator for the U.S. TAGs (United States Technical Advisory Group) to ISO/TC 212 and its WGs (Working Groups). Standards from CLSI are available both individually, directly through the ANSI webstore, and as part of a Standards Subscription. If you or your organization are interested in easy, managed, online access to standards that can be shared, a Standards Subscription may be what you need - please contact us at: or 1-212-642-4980 or Request Proposal Price.

Below are CLSI's best-selling standards. To find additional standards, please use the search bar above.

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Evaluation of Detection Capability for Clinical Laboratory Measurement Procedures; Approved Guideline -Second Edition (EP17-A2)

This document provides guidance for evaluation and documentation of the detection capability of clinical laboratory measurement procedures (ie, limits of blank, detection, and quantitation), for verification of manufacturersÆ detection capability claims, and for the proper use and interpretation of different detection capability estimates.

CLSI EP05-A3 (R2019)

Evaluation of Precision of Quantitative Measurement Procedures; Approved Guideline - Third Edition

This document provides guidance for evaluating the precision performance of quantitative measurement procedures. It is intended for manufacturers of quantitative measurement procedures and for laboratories that develop or modify such procedures.


User Protocol for Evaluation of Qualitative Test Performance; Approved Guideline-Second Edition

This document provides a consistent approach for protocol design and data analysis when evaluating qualitative diagnostic tests. Guidance is provided for both precision and method-comparison studies.   

CLSI EP25-A Vol. 29 No. 20

Diagnostic Reagents; Approved Guideline Stability of In Vitro Diagnostic Reagents; Approved Guideline

This document provides guidance for establishing shelf-life and in-use stability claims for in vitro diagnostic reagents such as reagent kits, calibrators, and control products.


Measurement Procedure Comparison and Bias Estimation Using Patient Samples - 3rd Edition

This guideline covers the design of measurement procedure comparison experiments using patient samples and subsequent data analysis techniques used to determine the bias between two in vitro diagnostic measurement procedures.

CLSI EP15-A3 (R2019)

User Verification of Precision and Estimation of Bias; Approved Guideline - Third Edition

This document describes the estimation of imprecision and of bias for clinical laboratory quantitative measurement procedures using a protocol that can be completed within as few as five days.


User Evaluation of Between-Reagent Lot Variation; Approved Guideline

This guideline provides a simple, practical, and statistically sound protocol to evaluate the consistency of patient sample results when a new analytical reagent lot replaces a reagent lot currently in use. This document is designed primarily for use with quantitative measurement procedures, but the same principles can be applied to measurement procedures that provide a clinically qualitative result based on a supplied quantitative measurement. This guideline is not intended for use with measurement procedures that only provide qualitative results. This guideline is intended for use in the clinical laboratory and is designed to work within the practical limitations that exist in that environment. This guideline is not intended to provide detailed procedures for reagent manufacturers. The needs of reagent lot-to-lot testing by manufacturers, and the resources available, are different from those of the clinical laboratory. However, reagent manufacturers may use this document to understand the types of verification studies that may be performed in their customersÆ laboratories.


Point-of Care Connectivity: Approved Standard-Second Edition

This standard establishes a set of specifications to allow seamless multivendor interoperability and communication between point-of-care devices, data concentrators, and clinical information systems. CLSI document POCT1 provides the framework for engineers to design devices, workstations, and interfaces that allow multiple types and brands of point-of-care devices to communicate bidirectionally with access points, data concentrators, and laboratory information systems from a variety of vendors.

As an interface standard, this document specifies the common communication interfaces and protocols between systems and devices. It facilitates the transfer of data to support the creation of point-of-care applications, services, and institutional policies. This document does not directly address specific pointof- care application and service level functions, such as device lockout and operator list management. This document specifies protocol, not policy. The interfaces specified support the communication required for engineers to build such application-level functionality. Specifying, building, and providing the applications to support these services are left to customers, device and information system vendors.

The only relationship of this point-of-care standard to the laboratory automation domain is through the use of the HL7 standard. In version 2.4,1 the HL7 standard was expanded to provide elements essential to laboratory automation, which also improved the HL7 standard for the entire laboratory-testing domain. These additions to HL7, along with four proposed new HL7 message triggers (see Section 4.1 in Appendix C of this CLSI standard), enable the point-of-care community to use HL7 as its electronic data interchange (EDI).

This specification also leverages several communication standards. It specifies the use of a single device transport protocol (IrDA TinyTP) running over two possible physical layers: IrDA-infrared, as specified by the Infrared Data Association (IrDA) and ISO/IEEE 11073-303002; and cable-connected, as specified by the IEEE 1073 lower-layers standard.3 This specification also utilizes local area networking standards such as IEEE 802.34 and protocols such as TCP/IP in cases where network connectivity is required.

CLSI C24-Ed4

Statistical Quality Control for Quantitative Measurement Procedures: Principles and Definitions, 4th Edition

This guideline provides definitions, principles, and approaches to laboratory quality control design, implementation, and assessment.


Interference Testing in Clinical Chemistry - 3rd Edition

This guideline provides background information, guidance, and experimental procedures for investigating, identifying, and characterizing the effects of interferents on clinical chemistry test results.


Evaluation of Commutability of Processed Samples; Approved Guideline - Third Edition

This document provides guidance for evaluating the commutability of processed samples by determining if they behave differently than unprocessed patient samples when two quantitative measurement procedures are compared.  


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