Isoelectric focusing under denaturing conditions.

The introduction of methods for the electrophoretic analysis of proteins under denaturing conditions (1,2) is something of a landmark in the development of methodologies for the analysis of proteins. Not only was analysis giving good correlation to molecular weight possible with small samples of complex mixtures of proteins, but in addition, analysis of normally insoluble proteins became possible in a relatively simple manner. These methods were based on solubilizing protein in sodium dodecyl sulfate (SDS) such that the intrinsic charge differences between proteins were overwhelmed by the relatively strong charge of the dodecyl sulfate ion, which resulted in very good correlation (for most, but not all, proteins) between electrophoretic mobility and molecular weight (see Chapter 6 in Vol. 1 of this series).