title: Nonamphoteric isoelectric focusing: II. Stability of borate-glycerol pH gradients in recycling isoelectric focusing.
abstract: By complexing polyols with borate in recycling isoelectric focusing and by varying the ratio of polyol to borate over the useful pH range of 4.0-6.0, it is possible to control pH. Twelve solutions of 0.1 M boric acid and varying glycerol concentration were used to vary pH in a twelve-compartment commercial recycling isoelectric focusing (RIEF) system. Various concentrations of boric acid were tested as anolyte, and various Tris(hydroxymethylamino)methane-borate buffer systems were tested as catholyte. Electroosmosis, hydrogen ion flow, and fluid balancing were characterized in two glycerol gradients; one was maintained at 0.06 pH/fraction and the other at 0.12 pH/fraction. In the latter case, ovalbumin (pI4.70) migrated to the pH 4.61 and 4.72 compartments. It is concluded that the borate-glycerol system can be adequately stabilized in RIEF for isoelectric purification of certain proteins.
authors.affiliation: Bioprocessing and Pharmaceutical Research Center, Philadelphia, PA.
authors.forename: P
authors.initials: P
authors.lastname: Todd
authors.forename: W
authors.initials: W
authors.lastname: Elsasser
mesh_terms: D001881:Borates; D004058:Diffusion; D005990:Glycerol; D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing; D011506:Proteins / Q000737:chemistry*; D012995:Solubility
chemical_list: D001881:Borates; D011506:Proteins; D005990:Glycerol