In muscle tissue, collagen serves as a major component of the endomysium. Collagen constitutes one to two percent of muscle tissue, and accounts for 6% of the weight of strong, tendinous muscles. A collagen may be defined as a protein containing sizable domain(s) of triple-helical conformation. Type IV collagen is a major macromolecular constituent of basement membranes and can be readily isolated from basement-membrane-rich tissues or highly vascularized tissues such as the placental villi. This collagen appears to be largely restricted to structures identifiable as basement membranes. In contrast, type VI collagen appears to be prevalent in several tissues even though it has been isolated largely from placental villi preparations. The extent to which type VII and VIII collagens are distributed is not known.
Store vial at -20° C or below. Avoid cycles of freezing and thawing. Centrifuge product if not completely clear after standing at room temperature. This product is stable for several weeks at 4° C as an undiluted liquid. Dilute only prior to immediate use.