October 7, 2004

Marina Kondratovich, Ph.D
Kristian Linnet, M.D., Ph.D
Daniel Tholen, M.S.

For more information about EP-17, “Protocols for Determination of Limits of Detection and Limits of Quantitation; Proposed Guideline,” please go to the NCCLS WEB SITE.

Linnet K. and Kondratovich M. Partly Nonparametric Approach for Determining the Limit of Detection. Clin Chem 2004;50:732–40.

EP17-A:Protocols for Determination of Limits of Detection and Limits of Quantitation; Approved Guideline will soon be published by NCCLS, Wayne, PA. This document contains a procedure that is substantially different than procedures currently being used by most manufacturers and method developers for these important characteristics. If recognized by the FDA CDRH, it will significantly change the performance characteristics reported for the methods. The procedures are based on ISO procedures, but modified for in vitro diagnostic methods, which often do not report results less than zero and do not have normally distributed results for the samples with no analyte present. The protocols include recommendations for reporting results at low levels, and recommendations for use of internationally harmonized terms, which do not include the use of the term “sensitivity”. This presentation describes the protocol for determining LoD and LoQ, and includes a brief review of the NCCLS consensus process, as it was applied to the development of this guideline.