Collagen pores determined by electron microscopy

Abstract

The existence and morphology of pores of the order of 150 A, in radius, within collagen fibrils is delineated. Structural features of collagen from air-dried kangaroo tail tendon, impregnated with Hg at a pressure of 10,800 psi., are compared with those of fibrils not exposed to Hg. A helical configuration of subfibrillar elements is suggested by the electron micrographs of individual fibrils. The possible use of Hg under hydrostatic pressure as a technique in staining and preserving the structure of biological materials for electron microscopy is advanced. These findings constitute a visual confirmation of the presence and probable size of small pores deduced from theoretical considerations of poresize distributions in collagen and leather, and provide additional information about the shape, location, and arrangement of such pores in collagen fibrils.