Use of phenol in the isolation of erythropoietic glycoprotein.

THE erythropoietic activity in the plasma of rabbits made anaemic with phenylhydrazine can be isolated as an acid glycoprotein. A dialysed and lyophilized ethanol fraction from heat-coagulated plasma consistently gives us a potent stable highly water-soluble preparation. Six laboratories have found good correlation in a comparative assay of a batch prepared by us1. Further di-ethyl-amino-ethyl cellulose column fractionation removes 40–50 per cent of inert protein and results in the active glycoprotein previously described2.