Precipitating polyclonal rabbit antiserum to human hemopexin. -globulin present in normal serum at a concentration of 0.8 to 1.0 mg/ml. Its molecular weight is 57,000. The carbohydrate content is 23%. It consists of one polypeptide chain. Purified hemopexin isolated from pooled human serum. Freund's complete adjuvan.