gamma,gamma'-(4,4'-Diamino-3,3'-biphenylylenedioxy)dibutyric acid (dicarboxidine) a safer substitute for benzidine type chromogens.

gamma,gamma'-(4,4'-Diamino-3,3'-biphenylylenedioxy)dibutyric acid (dicarboxidine) is a new chromogen developed as a safe substitute for conventional benzidine type reagents. The compound is water soluble and has a low distribution ratio organic phase/aqueous phase, which makes it superior for use with automatic analytical instruments. The stability of both dicarboxidine and its coloured oxidized form are better than and their sensitivity equal to that of o-dianisidine. Dicarboxidine is not mutagenic in Ames test. Studies in mice for two years failed to reveal any carcinogenic activity, studies in rats indicated only a marginal effect.