Purity ~90% (SDS-PAGE). Contains >10% bovine collagen type I and >0.5% non-collagen proteins. Molecular composition: [a1(III)]3 , native triple helix. Dissolved collagen retains the ability to form microfibrils, activate platelet aggregation and serve as a substrate for cell growth in culture Collagen was extracted from washed, dissected tissue into dilute acetic acid after mild pepsin treatment. Collagen type III was purified using differential salt precipitation. Contaminants: Contains >10% bovine collagen type I and >0.5% non-collagen proteins