Traditional ELISA typically involves chromogenic reporters and substrates that produce some observable color change to indicate the presence of antigen or analyte. Newer ELISA-like techniques use fluorogenic, electrochemiluminescent, and quantitative PCR reporters to create quantifiable signals.
ELISA is a laboratory technique that detects certain antibodies, antigens and other substances in your blood, pee or other bodily fluid. Laboratory scientists use this technique for several medical tests — from diagnosing infections to confirming pregnancy.
Learn about ELISA assays with Pierce Protein Methods. Our comprehensive guide covers principles, protocols, and applications, enabling precise and reliable results for your research.
Each ELISA measures a specific antigen, and kits for a variety of antigens are widely available. The ELISA pictured in Figure 1 is what is known as a sandwich ELISA, here two sets of antibodies are used to detect secreted products, e.g. cytokines. The method is stepwise in the order shown.
ELISA uses a specific antibody with a covalently coupled enzyme. The amount of antibody that binds the antigen is proportional to the amount of antigen present, which is determined by spectrophotometrically measuring the conversion of a clear substance to a colored product by the coupled enzyme.
An enzyme conjugated with an antibody reacts with a colorless substrate to generate a colored reaction product. A number of enzymes have been employed for ELISA, including alkaline phosphatase, horseradish peroxidase, and B-galactosidase. Principle of ELISA ELISA is a plate-based assay technique.
enzyme-linked immunosorbent assay (ELISA), biochemical procedure in which a signal produced by an enzymatic reaction is used to detect and quantify the amount of a specific substance in a solution.