ELISA Reagents

Enzyme-linked immunosorbent assay (ELISA) is an assay that incorporates antibodies and color change to identify an analyte. ELISA is used in many applications, including screening serum antibody concentrations, drug screening and allergen testing. ELISA is considered a "wet lab" analytic biochemistry assay as the sample and reagents are in solution. The ELISA protocol requires many different reagents in its’ five-step procedure: 1) antigens to coat the microtiter plate wells 2) blocking reagents for unbound sites to prevent false positive results; 3) antibodies 4) anti-(species) IgG conjugated to an enzyme; and 5) substrates that react with the enzyme to produce a colored product (indicating a positive reaction). In addition to the procedure reagents, additional reagents such as wash buffers, stop solutions and stabilizers can enhance the quality of the ELISA assay. When choosing individual reagents, or complete kits, it is helpful to know the sensitivity required and whether one is trying to detect an analyte or the antibody response to it. Quality reagents and some protocol tweaking will yield a reproducible assay with good results.