Soluble collagen in human serum.

Soluble collagen-like components in whole human serum and in serum fractions obtained after filtration on Sephadex G-zoo or after sucrose density gradient centrifugation were analyzed by micro-immunodiffusion and by immunoelectrophoresis. Antiserum to human skin collagen served as the reagent for the detection of the antigen. The collagen-like components were shown to exist in at least z, and possibly 4, molecular forms, which shared a common antigenicity, but differed in size, density and electrophoretic mobility. One of the components was eluted from the gel in the same area as the larger protein molecules of serum, while the other component appeared in the area of the smaller serum protein molecules. The use of antiserum to human skin collagen preparation to detect multiple collagen-like components in human serum offers a new and simplified method for further investigations in the area of collagen metabolism.