Chapter 15 Scanning Electron Microscopy of Embryos

Abstract

Publisher Summary This chapter provides descriptions of wet chemical, alcohol dehydration and critical point-drying methods that developed for routine preparation of sea urchin embryos for scanning electron microscopy (SEM) analysis in the secondary electron mode. Therefore, artifacts of specimen preparation and operational parameters of the SEM scope are reviewed. After the basic procedures of preparing specimens and the morphological information derived from SEM secondary electron images are obtained, then is the time to use SEM instrumentation and techniques for further bridging the gap between light microscopy (LM) and transmission electron microscopy (TEM) analyses. In particular, secondary electron images of the labeling of cell surfaces through markers such as latex spheres and colloidal gold coupled with improved techniques for preserving the integrity of hydrated molecules can vastly improve the detection and localization of a number of developmentally interesting macromolecules. Finally, backscatter electron imaging of structures differentially “stained” with various heavy metals in addition to colloidal gold markers offer unexplored opportunities. The main limits of these opportunities are inertia, time, and imagination.