Primary antibodies are essential research tools used to specifically detect and bind to target antigens such as proteins, peptides, or other biomolecules in a wide range of biological samples. They play a critical role in immunoassays and analytical techniques including Western blotting, immunohistochemistry (IHC), immunocytochemistry (ICC), immunofluorescence (IF), flow cytometry (FC), ELISA, and immunoprecipitation (IP).