Abstract
Extracts of human anterior pituitary glands were prepared by homogenization and high speed centrif ugation. The particle -free supernatant solutions were subjected to electrophoresis on paper, in starch grain and in starch gel. A preparative method for electrophoresis in starch gel was devised. Separation of serum proteins into 14 zones was obtained with this method and the patterns obtained with pituitary extracts showed three major zones, one of which was haemoglobin, and a variable number of other zones. Protein recovered after electrophoresis from portions of the gel was tested for gonadotrophin by the mouse uterus test. Gonado-trophic activity was found among the more slowly moving fractions and could not be correlated with any individual protein zones revealed by staining with nigrosine.