Localization of cholesterol in peripheral nerve: USE of [3H] digitonin for electron microscopic autoradiography

Abstract
Tritiated digitonin of high specific activity has been incorporated into fixation of adult rat sciatic nerve. Electron microscope autoradiograms developed four to thirteen days after coating indicate highest concentration of label over or near myelin sheaths. Label is observed over areas of reasonable myelin preservation as well as in areas of artifact and membrane disruption. The technique is suggested for use as a means of fairly specific localization of free cholesterol in tissues. In addition, the activity of the isotope used permits visualization of autoradiograms after short exposure times.