What are the common applications for secondary antibody conjugates?

Secondary antibody conjugates are used in a wide range of applications including Western Blotting, ELISA, flow cytometry, immunopurification, Immunohistochemistry (IHC), immunofluorescence, and more.

In all assays, secondary antibody conjugates help in the indirect detection, quantification, and purification of antigens by binding to the primary antibody which binds directly to the target antigen. Indirect detection using secondary antibody conjugates involves an extra immunolabeling step as compared to direct detection using primary antibodies. However, the additional step is worth it for the many advantages it offers, particularly in terms of increase in improved sensitivity, increased signal amplification, and higher flexibility. The increased sensitivity and signal amplification is a result of multiple secondary antibody conjugates binding to a single primary antibody, which brings additional reporter molecules to the antibody-antigen complex. 

Secondary antibody conjugates can be used with any primary antibody of the same host and species. Primary antibodies are typically unconjugated or conjugated to a limited range of reporter molecules. Secondary antibody conjugates are a much more versatile reagent. They facilitate access to a more diverse range of reporter molecules, improving flexibility in various labeling protocols.