This lyophilized fibronectin has been purified from human plasma where it is found as a dimer and has a size of 440-500 kDa with two similar subunits (220-250 kDa ) linked by two disulfide bonds. Fibronectin is a widely used broad range natural cell attachment factor. Fibronectin’s primary function is related to cell adhesion and attachment to extracellular matrix. Certain domains of Fibronectin have been found to play important roles that involve interactions with collagen, heparin and other cell surface glycosaminoglycans (GAGs). Fibronectin is ideal for coating of surfaces and is typically used at a concentration of 1-5 µg/cm2 . It is provided in user-friendly packaging for use and storage. Fibronectin is sterile filtered and is supplied as a sterile, lyophilized product.