A new, versatile, multiphasic buffer system for high-resolution sodium dodecyl sulfate-polyacrylamide gel electrophoresis of proteins in the relative molecular weight range of 300000-3000 Da is described. The system, based on the theory of multiphasic zone electrophoresis, allows complete stacking and destacking of proteins in the above M-r range. The buffer system uses taurine and chloride as trailing and leading ion, respectively, and Tris, at a pH close to its pK(a), as the buffering counterion. Coupled with limited variation in the acrylamide concentration, this electrophoresis system allows to tailor the resolution in the 6-200 kDa M-r range, with minimal difficulties in the post electrophoretic identification processes.