New diazo reagent for specific staining of conjugated bilirubin in tissue sections.

Abstract

A new technique is presented for the specific histochemical demonstration of conjugated bilirubin in tissue sections, using the diazonium salt of ethylanthranilate. The specificity of this method was proved by using test materials and cholestatic tissue sections. There was no diffusion artifact under the prescribed working conditions. The method is applicable to fresh cryostat sections and frozen sections of cold, formol-calcium-fixed tissues. The method could not be satisfactorily applied for the staining of total bilirubin. The method using 2,4-dichloraniline remains the best available technique for the histochemical demonstration of total bilirubin, while the technique with ethylanthranilate proves to be the most specific method available for the demonstration of conjugated bile pigments.