ELISA assay

General Introduction to ELISA Assay

ELISA Assay or Enzyme-Linked ImmunoSorbent Assay is a biochemistry technique which is used to determine if a particular protein is present in a protein sample and to quantify how much of the protein is present. ELISA is also used in immunology to detect the presence antibodies or antigens in a given sample.

How the ELISA Assay Works?

The ELISA assay utilizes two antibodies: one antibody is specific to the antigen of interest (i.e your protein of interest); and the 2nd antibody is coupled to an enzyme. The second antibody gives the Elisa assay its "Enzyme-linked" name or the EL of ELISA. This secondary antibody catalyzes chromogenic or fluorogenic changes in the presence of a chromgenic or fluorogenic substrate respectively.

Applications of the ELISA Assay

Since ELISA assay can detect the presence of antigen or the presence of antibody in a sample, it is a very important tool both for the determination of serum antibody concentrations (such as HIV tests or West Nile Virus tests) and also for detecting the presence of protein antigens in clinical samples.