Correlative LM, SEM and TEM of argentaffin cells

Abstract

The identification of small numbers of cells containing specific materials or having a particular location in a tissue can be observed cften in light microscopic (IM) sections by selective staining. In contrast, the same cells are often difficult to identify in alternate thin sections on grids by transmission electron microscopy (TEM). Grid bars produce periodic obstructions and consequently prevent the visualization of tissue continuity, making it difficult to identify landmarks. Also, the TEM image of a thin section of tissue does not correlate well with the thicker IM image. This is a matter of interpretation based on the different principles of image formation and the different levels of resolution.The purpose of this paper is to demonstrate a method which allows the same cells identified by IM to be more easily located in thin sections for TEM. This method combines the principles of backscattered electron imaging (BSI), secondary electron imaging (SEI) and heavy metal staining with scanning electron microscopy (SEM).