Backscatter electron imaging (BEI) of paraffin sections stained with heavy metal histopathologic stains, with observations on some variables encountered in BEI.

Using a recently developed annular photolithographic type backscatter detector, we studied a number of heavy metal stains used routinely in light microscopy. These were paraffin sections fixed with standard light microscopic fixation and dehydration techniques with no special modification made to them prior to coating of the slides with carbon for scanning observations. It was found that many of the stains that work in light microscopy will also provide good results in backscatter imaging if the differentiation of the staining is good. Studying the effects of varying accelerating voltages, it was discovered that optimum results and the most reliable data are achieved by comparative examination of the specimen at both a low and high voltage. This is necessary to prevent misinterpretation of data as a result of inadequate beam penetration of the sample.