Comparison of Scanning Transmission and Backscattered Electron Imaging in the Sem, Using Heavy Metal Stained Sections of Biological Tissue

Abstract

The Transmission Electron Microscope (TEM) has been used extensively for the study of biological tissues in thin section (50-100 nm). For sectioned material greater than 100 nm, the Scanning Transmission Electron Microscope (STEM) and the High Voltage Electron Microscope (HVEM) have become the only alternatives for the study of these tissues at a resolution better than that obtained with the light microscope. Recently, it has been shown(1) that tissue stained with heavy metal can be studied in the Scanning Electron Microscope (SEM) by Backscattered Electron (BSE) imaging to give results similar to those obtained with the TEM. Because BSE imaging is a method complementary to STEM, it seemed worthwhile to compare the two techniques using the same specimens and beam conditions.Direct observation of the total specimen is possible with BSE imaging without interference by grid bars. Therefore, an improved perspective of tissue-totissue structural relationships can be obtained at a resolution significantly better than that of the light microscope.