Enzyme linked immunosorbent essay (ELISA) is a biochemical technique used mainly in immunology to detect the presence of antibody or antigen in a sample. The Elisa has been used as diagnostic tool in medicine and plant pathology as well as quality control check in various industries.
Principle: Unknown amount of antigen (protein) is affixed to the surface and then specific antibody is washed over the surface, so that it can bind to specific antigen. The antibody-antigen complex is flooded with enzyme that can convert the complex to some detectable signal. For example, in case of fluorescence ELISA, when light is shown upon the sample, antigen/antibody complexes will fluoresce so that amount of antigen in the sample can be measured. Read more