Two-dimensional electrophoresis of small-molecular-weight proteins

Abstract

We have developed a procedure for two-dimensional separation of small-molecular-weight (9000-30,000), acidic (pI 4-6) proteins that allows the use of strips cut from horizontal isoelectric-focusing slab gels for the first dimension, and discontinuous gels containing sodium dodecyl sulfate and high concentrations of urea in the second dimension. This technique facilitates the screening of large numbers of samples and the evaluation of electrofocusing artifacts. We emphasize measures to prevent major problems encountered in the use of this technique, particularly those caused by diffusion and aggregation. We also describe an extension of the method which allows the two-dimensional comparison of many samples in a selected narrow pH zone of interest. © 1979.