Electron Microscopy: A Tool for Visualizing Chromatin

Abstract

The molecular biologist is fortunate that many of the macromolecules of interest can be visualized by the electron microscope, thus helping in the interpretation of biophysical and biochemical information. The problem arises in finding objective criteria for evaluating such images; gleaning the meaningful information and discarding the chaff. It is the goal of this article to set forth such guidlines to sharpen the student’s awareness of the characteristics of acceptable electron microscopic data. The evaluation of a micrograph, as other biophysical data, can and should be objective and not based on artistic merit. Progress in our understanding of chromatin structure has been accelerated by electron microscopy and will serve as an example for this discussion.

Research supported by the National Science Foundation Grants PCM76-01490 and PCM77-21493 and by the Division of Biological and Environmental Research, U. S. Department of Energy, under contract W-7405-eng-26 with the Union Carbide Corporation.