ELISA-Based Assay Development

The Enzyme-Linked Immunosorbent Assay (ELISA) is the most common and widely used immunoassay application. ELISAs are designed for detecting and quantitating substances such as peptides, proteins, antibodies, hormones, cytokines, drugs of abuse and their metabolites. A number of different assay formats are being used, dependent on the system being investigated. The simplest format involves coating of an antigen onto microtiter plates, followed by incubation with a specific antibody. The binding antibody or an appropriate secondary antibody is conjugated to an enzyme that typically catalyzes the formation of a colored product. Color formation is monitored spectrophotometrically and related to concentration of the antigen by calibration to a standard curve. When antigen is limited, a sandwich assay format is used in which the analyte to be measured is bound between two antibodies – the capture antibody and the detection antibody. Competitive assays are often used when the antigen is small and has only one epitope, or antibody binding site. ELISAs are typically performed in 96, 384, and even 1536-well polystyrene plates, and are easily robotized and adapted to high throughput screening.

BIO-SYNTHESIS, INC. has generated many polyclonal antibodies for ELISA and has developed optimized protocols. Most of our catalog antibodies have been tested in ELISA-type assays. They are able to detect antigens reliably, down to concentrations as low as 250 pg/ml. In addition, we have custom-made many polyclonal antibodies for ELISA-based applications required by our customers, including antibodies to phosphoproteins, enzymes, haptens, and drugs of abuse. BIO-SYNTHESIS, INC. offers a wealth of expertise in developing antibodies for ELISA-based applications. Please contact us with your specific application needs.