Improved Preservation of Tendon for Electron Microscopy through Wet Freeze-drying

Abstract

MOST of the information on the fine structure of biological tissues as revealed through electron microscopy has been gained from sections of material fixed with buffered osmium tetroxide, dehydrated in alcohols, and embedded in plastics. The degree of preservation of intracellular detail attained by such handling has been in general very consistent, and the preparatory techniques have been widely accepted as adequate. It has become evident in our recent work that, while some extracellular structures are also regularly well preserved, others seem to suffer considerable damage when processed in like fashion. This has especially been true in the case of tendon, where the component microfibrils appear to become widely separated (Fig. 1). The particular tendons under study are found in the leg of the domestic turkey, and they are of interest to us because they undergo calcification. It is obvious that in order to investigate the relationships between collagen fibrils and mineral crystallites tissue preservation is of the utmost importance.