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Updated: May 19, 2026

High-throughput and Comprehensive Drug Surveillance Using Multisegment Injection-Capillary Electrophoresis-Mass Spectrometry
Published on: April 23, 2019
The utility of immunoassays for urine drug testing
1Department of Pathology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA. semelanson@partners.org
Abstract:
Substance abuse is a significant problem in the United States, with cocaine, marijuana, alcohol and heroin as the most commonly abused drugs. This article focuses on urine drug testing to evaluate potential drug abuse or overdose in the emergent care setting using qualitative immunoassays. Discussion is included regarding the principles of how to validate qualitative immunoassays; how to decide on appropriate specimen type, test menu and cutoff; the limitations of immunoassays; how to communicate test results to clinicians; and use of urine drug testing at point of care.
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Enzyme-Linked Immunosorbent Assay
There are many different types of ELISAs, but they all involve an antibody molecule whose constant region binds an enzyme, leaving the variable region free to bind its specific antigen. Enzyme-substrate reaction allows the antigen to be visualized or quantified.

