The use of o-dianisidine for serum haptoglobin electrophoresis using cellulose acetate.

1. Due to the carcinogenicity of benzidine, a method by which o-dianisidine is used to stain serum haptoglobin is described. Serum haptoglobin is determined by electrophoresis using cellulose acetate as the medium. 2. A comparison of the two staining systems demonstrates good agreement. 0-Dianisidine can be substituted for benzidine without loss of specificity.