Serial Sectioning via Microtomy (or, How To Get Over 100 Consecutive Serial Sections On One TEM Gird)

Abstract

Serial sectioning of TEM blocks is a common technique. The more sections that are desired, the more complex the procedure becomes. Some of the problems faced are staining without losing or obscuring sections, appropriate block trimming, finding the area of interest in the next section, transferring sections to the grid. Here, I relate a set of techniques that permit the microtomist to regularly get over 100 consecutive serial sections on a single slot grid. Much of what is discussed below is not new, but by putting all of these techniques together I believe that a powerful tool for TEM is presented.The first issue that must be addressed is how to stain the sections on the grid without losing sections or obscuring sections with staining artifacts (e.g. lead pepper). The simplest solution is to stain the sample with both uranium and lead prior to embedding and not stain the sections on the grid.