Dye-binding method for rapid colorimetric determination of the cholestasis characterizing lipoprotein-X

Serum lipoproteins were stained by the addition of Sudan Black B solution. The normal lipoproteins and the excess of Sudan Black were removed with heparin and zinc acetate solution. The abnormal lipoprotein-X remained in the supernatant, the blue colour of which was measured. The empirically obtained constant was used for calculation, thus avoiding standardization.