Secondary antibodies facilitate the detection, sorting, and purification of target antigens. Using a secondary antibody, increases sensitivity, signal amplification, and flexibility for improved results. To enable detection, it is crucial to choose the secondary antibody that is specific for the antibody species and isotype of the primary antibody being used.

Secondary antibodies are used in various types of assays including flow cytometry, Western Blot, ELISA, and immunohistochemistry (IHC). In all assays, the secondary antibody binds to the primary antibody, which binds directly to the target antigen.