Chromic Gut sutures are absorbable sterile surgical sutures composed of purified connective tissue (mostly collagen) derived from the serosal layer of beef (bovine) or the submucosal fibrous layer of sheep (ovine) intestines. They are packaged in a solution of 90% isopropanol, 0.5% sodium benzoate, 0.5% diethylethanolamine, and water q.s. ad 100%. Chromic Gut is treated with a chromic salt solution.