Isoelectric focusing in immobilized pH gradients in presence of urea and neutral detergents

Publisher Website
Google Scholar
Abstract
The pK's of Immobilines, the reactive acids and bases used for establishing the pH in polyacrylamide gel matrices for isoelectric focusing with immoblized pH gradients, were measured in presence of urea (up to 8 M) and a neutral detergent'(2 % Nonidet P‐40). The temperature dependence of the pK's in 8 M urea was also investigated. ΔpK's due to the addition of urea were found to be higher for the acidic than for the basic Immobilines. Formulations are given to obtain 4 and 5 pH unit wide gradients with pre‐fixed extremes and linear in the presence of 8M urea. Such gels require, as pretreatment before the run is started, either an electrophoretic elution, by applying the voltage perpendicular to the direction of the pH gradient, or extensive washing in water, followed by drying and re‐equilibration in urea solution.