A sensitive, rapid, and economic radioimmunoassay of human growth hormone using ethanol-ammonium acetate.

An aqueous solution of 66 per cent ethanol and 6.6 per cent ammonium acetate has been used in the development of a relatively simpler and rapid as well as highly reproducible method of separation of antibody-bound and free hormones in the radioimmunoassay of human growth hormone (HGH). The present assay is sensitive to detect 20 pg. of hormone with a precision of plus or minus 5 per cent, hence, as little as 20 mul of plasma is required to perform the radioimmunoassay. Serum levels of HGH have been found to be approximately 70 per cent of the plasma concentrations in the same subjects.