Bovine type I, II, III, IV, and V collagens (each 1 mg/ml in 5 mM acetic acid) were mixed with an equal volume of neutralising buffer solution (0.1 M Tris-HCl [pH 7.5] containing 0.4 M NaCl and 10 mM CaCl2). Human type VI collagen was dissolved in 50 mM Tris...