Turbidity Produced by Hexamminecobaltic Chloride in Serum of Rabbits Injected Intravenously with Papain. ∗

Summary

1. Serum of rabbits following injection of chondroitin sulfate, crude papain, or several modifications of papain, became turbid following addition of hexamminecobaltic trivalent cation. Turbidity was directly related to amount of chondroitin sulfate-like material present in the serum. 2. The precipitate produced by this cation contained most of the non-dialysable S³⁵ activity present in the circulation following injection of crude papain, was metachromatic when redissolved, and did not form after incubation of serum with testicular hyaluronidase. 3. Addition of hexamminecobaltic chloride to dilute, dialysed serum is a useful way of demonstrating sulfated mucopolysaccharides in serum at levels exceeding 250 μg/ml.