This is a very comprehensive troubleshooting guide for all types of immunoassays. Instructions are provided on use of the chapter to investigate and improve unsatisfactory assay performance, through root cause analysis. Each type of performance issue has a separate section, with a list of possible causes that can be used as a starting point. For each possible cause, information is provided to allow the reader to dismiss unlikely causes immediately, resulting in a shortlist of possible causes that are consistent with the facts. Then a suggested course of action provides a strategy for identifying the most likely cause(s) from the shortlist. Recognizing that the investigation of many immunoassay problems involves a user and a manufacturer working together, a checklist of useful information is provided for the user to prepare for an efficient dialogue with the manufacturer. Finally a case study for each type of problem is provided, with the eventual solution.

David Wild’s career spans 40 years in diagnostics, medical devices, pharmaceuticals and biotechnology. As a University of London undergraduate, he won the Driver Prize for Biochemistry after discovering an extra electron transfer step in photosynthesis. As leaders of the University Biochemistry Society, he and his girlfriend Cindy (now wife) hosted lectures by Sir Hans Krebs and Roger Ekins. After graduation, he worked first as a molecular biologist at a pharmaceutical company R&D laboratory, then, for 25 years, in immunodiagnostics, managing product development and industrial engineering projects. More recently he managed large medical device R&D and operational projects. He worked for Amersham, Kodak, Johnson and Johnson, Bristol-Myers Squibb and ConvaTec. His Director level positions include Research and Development, Design Engineering, Global Manufacturing, and Strategy. He indulges his passion for immunoassays as Managing Editor of The Immunoassay Handbook and lectures, trains and consults on development, manufacturing and marketing strategies, and how to integrate and execute them.

Jianwen He (M.D. & Ph.D.) is currently the R&D Sr. Manager for BioMerieux Shanghai Biotech with responsibility for managing rapid testing and other immunoassay development. Prior to joining BioMerieux, Jianwen worked as a staff scientist and R&D manager for assay development in the Immunoassay Diagnostics Center of Beckman Coulter, Inc for 10 years, where he helped design and develop many CLIA assays including Access Inhibin A. Jianwen also worked as North Asia commercial manager for DiaSorin S.p.A. for a couple of years, where he managed the RIA, ELISA, and CLIA immunoassay business for a matured market. Jianwen has gone through immunoassay from discovery, research and development to commercialization. Jianwen has a Ph.D. in molecular virology.

Problem-solving, troubleshooting, cause-and-effect, bias, inaccuracy, drift, imprecision, control failure, signal level, low binding, high binding, ED₅₀, non-specific binding, linearity, dilution, recovery, clinical classification, sensitivity, specificity, reference interval, negative values, correlation.