A Serum Protein present in Pregnant Women

Abstract

SMITHIES¹ has briefly mentioned a protein band which he found in the starch-gel electrophoretograms of sera from about 10 per cent of women who were either in late pregnancy or had recently delivered. In the work reported here, a much higher frequency has been found for what is probably the same protein band. In some runs in a borate gel at pH = 8.5, under essentially the same conditions as described by Smithies², the protein of the investigation reported here migrated at a rate slightly slower than the first haptoglobin band of Hp 2–2 sera to which hæmoglobin had been added (Fig. 1). In other runs, the two were not separated. Accordingly, the typings for presence and absence of the band in Hp 2–2 sera are not included in the data given here although it was undoubtedly present in the majority of such sera.