Scanning and transmission electron microscopic studies of human intestinal mucosa.

The scanning electron microscope is capable of 25 mmu resolution combined with a great depth of focus, features which make the technique of value in the study of the intestinal mucosa. Surgical biopsies and postmortem specimens of small intestine have been examined using scanning and transmission electron microscopy. In biopsies, at low magnification, the villous pattern is seen while at higher magnification details of cell surfaces may be observed. Some features are best observed using scanning microscopy to examine dewaxed thick histological sections. In necropsy specimens villous architecture can still be satisfactorily assessed and details of the villous cores are seen, their collagen skeletons apparently less robust than the villi of the fresh biopsy. Scanning microscopy can extend the three-dimensional study of the small intestinal mucosa beyond the limits imposed by the resolution of the dissecting microscope.