title: On the mechanism of the cold ethanol precipitation method of plasma protein fractionation.
abstract: Given the negligible difference in the value of the dielectric constant of water at 20 degrees C and that of ethanol solutions at low temperatures, the often advanced explanation for the precipitation of plasma proteins by the cold ethanol process, as being due to a reduction of the dielectric constant and the resulting increase in interprotein charge interactions, is not tenable. It is shown by a surface-thermodynamic approach that, upon dehydration by ethanol, isoelectric serum albumin molecules as well as isoelectric serum gamma globulin molecules will attract each other to a sufficient degree by van der Waals forces to become insoluble in the ethanol-water mixtures used.
authors.affiliation: Department of Microbiology, State University of New York, Buffalo 14214.
authors.forename: C J
authors.initials: CJ
authors.lastname: van Oss
mesh_terms: D001798:Blood Proteins / Q000302:isolation & purification*; D011232:Chemical Precipitation; D003080:Cold Temperature; D000431:Ethanol; D006801:Humans; D012995:Solubility; D013500:Surface Tension; D013816:Thermodynamics; D014867:Water
chemical_list: D001798:Blood Proteins; D014867:Water; D000431:Ethanol