Development of a sandwich ELISA test for arginase measurement based on monoclonal antibodies

Human arginase was purified from liver and two monoclonal antibodies (MAbs) , HA1 and HA2, were produced by fusion of spleen cells from an arginase-imm unized BALB/c mouse and the NS-1 myeloma cell line. Both MAbs were of the I gG(3) subclass and contained the kappa light chain. HA1 inhibited arginase activity, suggesting that it binds to the arginase catalytic site. HA1 and a horseradish peroxidase-conjugated polyclonal rabbit anti-human arginase a ntibody were used to develop a sandwich enzyme-linked immunoadsorbent assay (ELISA) for the quantification of human arginase, which can be used in the 1 to 300 ng/mL range. Because of its sensitivity and specificity, this MAb can be successfully applied to the ELISA quantification of arginase in ser um and culture supernatants.