Development of preparing small-amount samples for transmission electron microscopy.

The means of examination of small-amount samples by transmission electron microscopy (TEM) is described. In this study, the amount of cells necessary for TEM was examined by using a KMU-100 cultured cell line. Floating cells diluted with phosphate buffer solution (PBS) to several concentrations, were gathered in the tip of Beem capsules by means of centrifuge. After fixation, dehydration, and embedding with Epon 812, the samples were cut with a diamond knife, followed by electron staining, and examined by TEM. As a result, we learned that an amount of cells over 1 x 10(3) could be observed by TEM. In spite of cell damage through this procedure, the microscopic structures of the cells were relatively maintained compared with the original cell monolayers. In the near future, it may be possible to examine the sorted cells by flow cytometry (FCM) with TEM.