Abstract
Simultaneous demonstration of two different antigens in a single cell was performed on the electron microscopic level by combined staining with both HRP-labeled antibody and ferritin-labeled antibody.
For HRP-labeled antibody method, 4-chloro-1-naphthol was employed as the substrate in place of diaminobenzidine to visualize the reactive sites, since the final product of diaminobenzidine was not dense enough to show the localization of antigens in high magnification in electron microscopy.
Two groups of enzymes, α-amylase and chymotrypsinogen A or α-amylase and trypsinogen, were found to be present concurrently in a single zymogen granule. This pattern of the distribution of enzymes was recognized in all the zymogen granules found in a section. These results support the view of Scheele and Palade (1975) and that of Tartakoff et al. (1975) within the limits of the final step of the secretory process, who maintain the opinion of parallel processing of the proteins in the pancreas.
