What is a Sandwich ELISA?

In a sandwich ELISA, two antibodies specific to different epitopes on the target antigen are used. A capture antibody is immobilized on the microplate well to bind the antigen, and a detection antibody binds to a second site on the antigen to enable signal generation.

Sandwich ELISA is widely used for quantitative analysis because of its high specificity and sensitivity. If the detection antibody is not enzyme‑conjugated, an additional enzyme‑linked secondary antibody is required to generate a detectable signal.