Characterization of human growth hormone from acromegalic pituitary tumors

Human growth hormone (HGH) was extracted from acromegalic pituitary tumors at pH 10.5 and precipitated with ammonium sulfate at 20–40% saturation. It was purified on a Sephadex G‐100 column to yield monomeric HGH. The tumor‐HGH was indistinguishable from the authentic one in polyacrylamide gel electrophoresis at pH 8.3 or in the presence of sodium dodecyl sulfate, high‐performance liquid chromatography, radioimmunoassay, peptide map, amino acid composition and N‐terminal partial amino acid sequence. The tumor‐HGH is active in the tibia assay and body weight gain test in hypophysectomized rats with comparable potency to that of the authentic sample.