Preparation and properties of serum and plasma proteins. IV. A system for the separation into fractions of the protein and lipo-protein components of biological tissues and fluids. - Cohn,E.J.; Strong,L.E.; Huges Jr,W.L.; Mulford,D.J.; Ashworth,J.N.; Melin,M.; Taylor,H.L. (J. Am. Chem. Soc., 1946)