PARTITION OF PARATHYROID HORMONE ON SEPHADEX G-100.

A study was made of the parti- tion of parathyroid hormone on the poly- saccharide gels, Sephadex G-50 or G-100, packed in columns operated under identical conditions; Sephadex G-100 afforded the more efficient separation of the hormone. Physical studies indicated that the hormone recovered from columns of Sephadex G-100 was better than 90% pure polypeptide with molecular weight near 10,000. Anomalous elution of the hormone occurred with G-100 columns equi- librated with 1M acetic acid; this phenomenon was attributed to adsorption of the hormone to the Sephadex gel rather than to altered conformation of the hormonal polypeptide. (Endocrinology 75: 290, 1964) I N A STUDY of the partition of parathy- roid extracts on polysaccharide gels, it was found that Sephadex G-100 afforded more efficient large-scale fractionation of parathyroid hormone than the method de- vised by Rasmussen and Craig (1) using Sephadex G-50. The new method reported here has been valuable in the preparation of hormone for chemical purposes and for ob- taining pure test antigen to be used in a sensitive immunoassay (2).