Plain gut absorbable sterile surgical sutures are composed of purified connective tissue (mostly collagen) derived from the serosal layer of beef (bovine) intestines. They are packaged in a solution of 89% isopropanol, 10% water and 1% triethanolmaine. The manufacture of catgut raw material, consisting of long ribbons of highly selected serosal tissue, ensures: purity of collagen for optimal tensile strength and in-vivo performance, surface smoothness to facilitate knot run-down and knot strength, due to electronic polishing of each strand. Plain gut sutures are indicated for use in general soft tissue approximation and/or ligation, including use in ophthalmic surgery, but not in cardiovascular or neurological surgery.