Purification of canine prolactin and growth hormone by fast protein liquid chromatography

Prolactin and growth hormone are two peptide hormone with a very similar structure. A simple method is described for the simultaneous purification of these two peptides from canine pituitary extract by fast protein liquid chromatography. After extraction at pH 5.0 and 9.6 and anion-exchange chromatography on a MonoQ column, prolactin and growth hormone are then separated by gel filtration chromatography on two Superose columns coupled in series. The different fractions of the purification scheme are checked for the presence of the peptide hormones by sodium dodecyl sulphate gel electrophoresis in the Pharmacia PhastSystem. Each hormone is also characterized by its behaviour in a Western Blotting Detection System.