Recovery of prolactin from acetone-dried human pituitary glands.

An improved method is described for the purification of prolactin from the same batch of acetone-dried pituitary glands which is used for the isolation of other anterior pituitary hormones. The residue obtained after the extraction of the glycoprotein fraction from the pituitary acetone powder was extracted for growth hormone. The supernatant after the precipitation of growth hormone at 50% ethanol concentration was adjusted to 85% in ethanol. To the supernatant obtained from that step an equal volume of acetone was added to precipitate the 'PRL fraction.' This fraction was further purified by gel filtration on Sephadex G-100, ion-exchange chromatography on DEAE-cellulose and isoelectric focussing. A yield of 23 mg prolactin, 37 U/mg, was obtained per 1000 g pituitary acetone powder.