Determination of Horseradish Peroxidase (HRP) Using Amplex® Red and the SynergyTMHT Microplate Reader

Introduction Enzyme linked immunosorbent assays (ELISA) have been used to quantitate a wide range of compounds and pathogens for almost 40 years. Initially radioactivity was used to quantitate the assays, but radioimmunoassays (RIA) have been replaced with assays utilizing enzymes to obtain colorimetric results. Recently new substrates have been developed to produce fluorescent and luminescent products. The basic tenet of the new assays remains the same as colorimetric assays. The substrate is converted into a measurable compound by the enzymatic activity of proteins conjugated to an antibody, which confers specificity.