Determining Sizes and Distribution of Sizes of Spherical Bodies such as Chromaffin Granules in Tissue Sections

Abstract

QUANTITATIVE microscopy is difficult at the ultrastructural level because many organelles and inclusions have irregular shapes and the images represent chance sections through bodies of unknown orientation. Size determination for chromaffin granules is easier than for many other inclusions or organelles because their profiles are usually rounded in section and in isolated granule preparations (Fig. 1) implying a spherical form and so orientation presents no problem.