An indirect ELISA (Enzyme-Linked Immunosorbent Assay) is a common biochemical technique that detects an antibody using a labeled secondary antibody. This assay is primarily used to detect the total antibody amount in a sample. This method is commonly utilized to diagnose infection and to quantify antibodies against an invading antigen.

RayBiotech indirect ELISA kits employ a specific antigen-coated 96-well plate. A sample containing the primary antibody is incubated into the wells and the antibodies present bind to the immobilized antigen. Next, the wells are washed and a biotin-labeled detection antibody that recognizes the primary antibody is added. After washing away unbound antibodies, an HRP-conjugated secondary antibody is then added, and when combined with a substrate, produces a signal amplification that is directly proportional to the amount of bound sample antibody.

The indirect ELISA kits are highly sensitive, because multiple labeled antibodies can bind a single antigen and there is maximum primary antibody binding since it is not labeled. It is also adaptable allowing for different primary antibodies to be used with a single biotin-labeled detection antibody. Furthermore, different detection systems can be used with the same primary antibody (colorimetric, chemiluminescent, etc.). Finally, this format is lower cost since fewer labeled antibodies are needed.

How It Works