Enzyme-Linked Immunosorbent Assay (ELISA) is a widely used diagnostic tool that allows scientists to detect and quantify specific molecules such as proteins, antigens, or antibodies. Are you trying to discover the major steps without getting bogged down in the details? Here is what you need to know.


  1. Addition of antibody to microtiter well
  2. Addition of a sample that contains the suspected antigen
  3. Addition of an enzyme-linked secondary antibody to bind with the antigen
  4. Addition of the enzyme-substrate
  5. Visualization of color and its quantification using a microplate reader (uses spectrophotometry to detect color)

Higher color intensities correspond with more antigens in the sample.

Antigen (green) sandwiched by primary and enzyme-linked secondary antibodies. Source – Wiki commons


  • Courtney Simons

    Dr. Courtney Simons has served as a food science researcher and educator for over a decade. He holds a Bachelor of Science in Food Science and a Ph.D. in Cereal Science from North Dakota State University.