The collagen showed fibrillar structure in the samples irradiated with doses up to 10 kGy but at the higher dose of 20 kGy, the fibrillar structure became less distinguishable. According to Cosgrove, Collins, Grant, and Allcock (1971) hydrogen was given off by collagen when subjected to g-ray resulting in the loss of stabilising hydrogen bonds with consequent (partial) collapse of native triple helix structure. Cheung, Perelman, Tong, and Nimni (1990) also reported significant damage to the polypeptide backbone of collagen at doses above 10 kGy.