Ethicon Sutures. Chromic Gut. 635H 4-0 FS-2 27" 36/BoxThe chromic gut suture is an absorbable, sterile surgical suture composed of processed and purified connective tissue made mostly of collagen from either the serosal layer of beef or the submucosal fibrous layer of sheep intestines. Best use includes general soft tissue approximation or ligation. Ethicon Sutures. Chromic Gut. 635H 4-0 FS-2 27" 36/Box