Improved reaction buffers for solid-phase enzyme immunoassay without interference by serum factors.

A gelatin moderately digested by a protease, was as effective as original gelatin to remove the interference by serum factors with a sandwich immunoassay for insulin. Digestion of gelatin resulted in decrease in the viscosity, and the buffer containing the digested gelatin did not show gelation at 4 degrees C. Therefore the buffer involving the digested gelatin might be widely useful for the immunoassay without interference by serum factors.