Amphoteric, isoelectric immobiline membranes for preparative isoelectric focusing.
Amphoteric, isoelectric agarose membranes, as devised by Martin and Hampson [Martin, A.J.P. and Hampson, F. (1978) J. Chromatogr. 159, 101-110], are found unsuitable for blocking electroendosmosis in multi-compartment electrolysers during preparative isoelectric focusing, due to the poor and highly unpredictable incorporation of carboxyls and amino groups on the polysaccharide moiety. New, polyacrylamide-based membranes are described, containing as buffers and titrants the Immobiline chemicals used to produce immobilized pH gradients. These new membranes are supported on both faces by a non-woven polypropylene cloth, a material exhibiting minimal adsorption properties for proteins. Due to the extensively developed Immobiline technology, membranes with highly predictable isoelectric points, well-defined buffering capacity and conductivity can be synthesized at any pH value along the pH 3-10 scale. They are effective in blocking electroendosmosis even when the delta pH on either side of the membrane is as high as 1.5 pH unit.
Swiss Federal Institute of Technology, Institute of Chemical Engineering, Lausanne.
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P
Wenger
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M
de Zuanni
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P
Javet
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C
Gelfi
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PG
Righetti
D000180:Acrylic Resins; D002021:Buffers; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007525:Isoelectric Focusing / Q000295:instrumentation* / Q000379:methods; D008567:Membranes, Artificial; D011126:Polypropylenes; D012685:Sepharose; D000099166:Polyacrylamides
D000180:Acrylic Resins; D002021:Buffers; D007202:Indicators and Reagents; D008567:Membranes, Artificial; D011126:Polypropylenes; D012685:Sepharose; D000099166:Polyacrylamides