EVIDENCE OF RAT TAIL TENDON PROTEOGLYCANS AT EMISSION FIELD SCANNING ELECTRON-MICROSCOPY

Alcian blue (AB) in critical electrolyte concentration (CEC) was used for scanning electron microscopy (SEM) on rat tail tendon. Segments wi th diameters of 4 to 9 nm are evident in the perifibrillar area with t heir lengths ranging from 180 to 400 nm. Frequently the segments adher e closely to collagen gap zones. Segments are not evident either in sp ecimens fixed in glutaraldehyde or in specimens stained with AB in CEC solutions previously treated with glycanolytic enzymes. The segments suggestively correspond to electrodense filaments evident in transmiss ion electron microscopy (TEM) if the rat tail tendon is similarly trea ted (Scott, 1981). It may be concluded that AB in CEC solutions can be utilized for SEM investigations and represents a good method for the detection of the threedimensional disposition of proteoglycans (PG) an d their interaction with collagen.