Description: The B-T21 antibody reacts with the p35 subunit of human interleukin-12 (IL-12). IL-12 is a 70 kDa heterodimeric cytokine composed of two covalently linked chains, p40 and p35, and is secreted primarily by activated B cells. For optimal detection of human IL-12 p70 by ELISA, a combination of purified B-T21 antibody for capture and biotinylated C8.6 antibody for detection is recommended.