Microdissection by ultrasonication after prolonged OsO4 fixation: a technique for scanning electron microscopy.

A new method of tissue preparation for electron microscopy is described for the selective dissection of mammalian tissues. This technique, based upon brittlization by prolonged osmication, dehydration to pure acetone and subsequent ultrasonication, has been especially useful for the SEM visualization of microcirculation and basal laminas. Epithelial cells of treated tissues were largely fragmented and removed, whereas collagen containing materials, notably epithelial and vascular basal laminas, withstood the vibratory insult. The extent of epithelium and basal lamina removal depended upon tissue type and duration of ultrasonic treatment. Alone or in conjunction with specific enzymatic pretreatment, this new technique offers a method to better visualize known and unrecognized histological relationships.