Histochemical detection of glycogen usingGriffonia simplicifolia agglutinin II

Summary

The utility of a lectin fromGriffonia simplicifolia (GSA II) for demonstrating glycogenin situ was tested on fixed paraffin-embedded sections of a variety of tissues from rodents and man. The histochemical specificity of GSA II conjugated to horseradish peroxidase (GSA II—HRP) for glycogen was documented by the lability of such staining on adjacent sections treated with either malt diastase orα-amylase. In some tissue sites, the lectin—HRP conjugate imparted cytoplasmic staining that was diastase- and amylase-labile but resisted digestion withN-acetylglucosaminidase. Reactivity in the latter sites was attributed to glycogen and occurred in cell types having well-documented glycogen content, including liver hepatocytes, skeletal muscle fibres and polymorphonuclear leukocytes. In other tissue loci, GSA II binding was confined to cell surfaces or intracellular compartments, was not affected by prior diastase or amylase digestion, but was abolished withN-acetylglucosaminidase. Staining in these sites was attributed not to glycogen, but instead to glycoconjugate having sugar chains terminated withN-acetylglucosamine. These findings document the affinity of GSA II for glycogenin situ but do not conflict with the biochemically demonstrated affinity of GSA II for terminalN-acetylglucosamine. The results reported here show that the GSA II—HRP method may be useful for detecting physiological or pathological changes in the glycogen content of cells.