A histochemical study of the proteins of precollagen fibers in regenerating connective tissue

An inquiry was made into the action of weak solutions of acetic acid, alkali, and citrate buffer on precollagen and collagen fibers of regenerating connective tissue. Precollagen and collagen fibers were studied with the aid of Gomori's method, the method for acylamidcarboxyl groups, and van Gieson's method. Precollagen fibers in the regenerating connective tissue are hardly soluble in the citrate buffer solution and acetic acid but they are readily soluble in alkali. From the moment of its appearance in the regenerating connective tissue, procollagen is well soluble in the citrate buffer solution, alkali, and acetic acid. Precollagen solubility falls with the maturation of connective tissue.