What are the differences between indirect ELISA and sandwich ELISA?
Indirect ELISA and sandwich ELISA are two types of enzyme-linked immunosorbent assays used in laboratory testing.
In indirect ELISA, the antigen is immobilized on the surface, and a primary antibody binds to the antigen. Then, a secondary antibody linked to an enzyme is added to detect the primary antibody.
In sandwich ELISA, the antigen is captured by a primary antibody that is immobilized on the surface. A second antibody linked to an enzyme is then added to bind to a different epitope on the antigen, forming a "sandwich" complex.
The main difference between the two methods is the way in which the antibodies are used to detect the antigen. In indirect ELISA, the primary antibody is detected by a secondary antibody, while in sandwich ELISA, the antigen is "sandwiched" between two antibodies for detection.