Soluble compound electron microscope (EM) autoradiography: a resolution source to test redistribution of soluble tritiated compounds during processing.

The development of a resolution source that can be labeled with either a soluble or insoluble tritiated compound, and of a method for applying a dry, uniform monolayer of emulsion is reported. Influences due to redistribution of the soluble isotope during emulsion coating were measured by comparing the grain density distributions around the resolution source for soluble tritiated proline (3H-PRO) with that obtained for cross-linked tritiated bovine serum albumin (3H-BSA). The grain density distributions resulting from a standard method of emulsion application (partly gelled/loop method) are compared to that obtained from a dry stripping film. It was found that only the dry stripping film gave a grain distribution which was statistically not different for the soluble and insoluble specimens.