Electron microscopic detection of the cryptantigen AhumHP (Friedenreich antigen) on human erythrocytes by means of gold-labelled agglutinin from Helix pomatia.

Using the gold-labelled agglutinin anti-AHP from Helix pomatia (edible snail) the ultrastructural site and distribution of the cryptantigen (Friedenreich antigen) AhumHP was revealed on neuraminidase treated human O and B erythrocytes. On A1 and A2 cells the antigen was demonstrated simultaneously with the blood group antigen A by labelling the cells with anti-AHP-ferritin followed by removing the neuraminic acid and labelling with anti-AHP-gold. The cryptantigen is focally distributed on the cell surface.