Type III collagen is present in the walls of arteries, intestines and the uterus, where it strenghtens the connective tissue. Patients with defects in the type III collagen (ex. Ehlers-Danlos syndrome) are at risk of rupture of major arteries or the intestine. Can be used for detection of collagens by ELISA. Has been used successfully for immunohistology on frozen unfixed sections of human (3) and kangaroo (4) skin, and of new canine tissue associated with biomaterial implants (2,5). If fixation of tissue is required, acetone or ethanol is recommended.