He was head of the cytochemistry laboratory when he retired in 1974. While at Yale University he introduced glutaraldehyde as a fixative for electron microscopy and cytochemistry. Popularly used in immunofluorescent cytochemistry where the fluorescence cannot be archived. In cell membrane cytochemistry, perylene is used as a fluorescent lipid probe. Immunofluorescence, cytochemistry, the immunocytochemistry and FISH are also used in order make a correct diagnosis.