Steps in the Development of a Validatable Immunoassay

This section elucidates some of the practical aspects that should be considered while developing an immunoassay. Although written with an emphasis on the sandwich assay format, and more specifically ELIS As over RIAs and ECL assays, it also applies to the competitive assay format. A systematic approach for immunoassay method development may consist of the steps shown in Fig. 3.3. 

The scope of the method development activity will depend on its intended use necessary information includes (1) the type of studies the method would support (e.g., preclinical or clinical), (2) the sample matrix (e.g., serum, plasma, urine, cerebrospinal fluid, etc.), (3) the expected range of analyte concentration in the samples, (4) the presence of potential interfering compounds in the study samples (e.g., rheumatoid factor, binding proteins, antibodies), and (5) the acceptable level of variability in the results. This information, combined with the availability of critical reagents and the technology platform to be implemented, plays a critical role in selecting the assay type and format. 

DEVELOPMENT OF LIGAND BINDING ASSAYS FOR DRUG DEVELOPMENT SUPPORT 

Defining the scope of the method Support for PK/PD/other studies Desired sensitivity Matrix of study samples Sample collection and storage conditions Assay format/technology platform 

Characterized material for calibrators and controls Critical reagents with proper documentation Microplate reader and washer Data reduction software 

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