Indirect ELISA Advantages

Indirect ELISAs also involve attachment of the antigen to a solid phase, but in this case, the primary antibody is not labeled. An enzyme-conjugated secondary antibody, directed at the first antibody, is then added. This format is used most often to detect specific antibodies in sera.

Compared to other immunoassay methods, there are many advantages of ELISA. ELISA tests are more accurate. They are considered highly sensitive, specific and compare favorably with other methods used to detect substances in the body, such as radioimmune assay (RIA) tests. ELISA possesses the added advantages of not needing radioisotopes (radioactive substances) or a costly radiation counter (a radiation-counting apparatus).

High Sensitivity

  • More than one labeled antibody is bound per antigen molecule


  • Different primary detection antibodies can be used with a single labeled secondary antibody


  • Fewer labeled antibodies are required