ISSN:
0173-0835
Keywords:
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
A simple and accurate method for the monitoring of the voltage distribution across horizontal slab gels in isoelectric focusing is described. Voltage is measured by passing a single Pt wire electrode (connected to an external voltmeter and to one of the electrodes through the power supply) through holes in the apparatus lid, bored at 5 mm distance from one another across the migration path. Conductances along the migration path calculated from direct voltage measurements are by one order of magnitude lower than those measured by conductimetry on gel slice eluates. Segmental resistances calculated from the measured voltages across adjacent holes in the lid during isoelectric focusing (IEF) add up to the total resistances across the gel obtained from the voltage and current readings on the power supply. In confirmation of previous reports, segmental resistance in IEF was shown to increase dramatically with time, with maxima shifting progressively from pH 4 to 5 in a representative pH3-10 gradient. Joule heat production in IEF decreases with increasing molecular weight of the carrier ampholytes.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/elps.1150050303
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