Two-dimensional polyacrylamide gel electrophoresis: an improved method for ribosomal proteins

A two-dimensional electrophoresis system for analysis of ribosomal proteins with several advantages over previous systems is described. The general features of this system are: (1) first-dimension separation on the basis of mobility at pH 5.0 in 8 m urea and 4% polyacrylamide; (2) second-dimension separation on the basis of molecular weight using dodecyl sulfate detergent; (3) rapid electrophoretic shift between first- and second-dimension separation conditions; (4) high resolution separation can be obtained on 10-cm² slabs with proteins from approximately 100 μg of ribosomal subunits; (5) capacity for handling up to 10 samples at a time, with electrophoresis complete within about 10 hr; and (6) the apparatus is relatively simple and inexpensive to construct and use.