Secondary antibodies

Secondary antibodies are immunoglobulins that specifically bind to primary antibodies rather than directly binding to target antigens. They recognize the constant region (Fc region) of the primary antibody and are commonly labeled with enzymes or fluorophores for detection purposes. They are widely used in immunoassays such as Western blot, ELISA, immunohistochemistry (IHC), immunofluorescence (IF), and flow cytometry to provide signal amplification and improve detection sensitivity. Because multiple secondary antibodies can bind to a single primary antibody, they significantly enhance assay performance and signal strength. Secondary antibodies are selected based on the host species and isotype of the primary antibody and are available in various conjugated forms such as HRP, AP, and fluorescent dyes for different experimental applications.