Anti-C4B_2 antibodies are used in the immunodetection of the protein complement component 4B (Chido blood group), copy 2. Synonyms for this target antigen include complement C4-B-like. A number of C4B_2 antibodies have been mentioned in research publications and have associated citations. Immunohistochemistry is a widely used application for these antibodies. ELISA and Western Blot are also common applications.