STRUCTURE OF RAT TAIL TENDON COLLAGEN EXAMINED BY ATOMIC-FORCE MICROSCOPE

The Atomic Force Microscope (AFM) was used to inspect collagen fibrils deposited on mica sheets at different fibrillogenesis times. Collagen was obtained from rat tail tendon fibers. Various fibril forms were o bserved, together with the characteristic periodic intra-fibril struct ure (D-bands). The fibril thickness, width, D-band periodicity and dep th were measured and the statistical distribution of these parameters at 1, 2, 5, 10 and 15 days of in vitro fibril formation time was calcu lated. The fibrils showed an increasing size with time, but the band i nterval measure remained stable. The band depth, after an initial incr ease, exhibited a relative steadiness. The results indicate that AFM o ffers, at low resolution, images qualitatively similar to those obtain ed with electron microscopy, but with less manipulation of the sample. A quantitative evaluation of collagen structural features in the nano meter scale is made possible by AFM.