The Bio-Rad PROTEAN II xi Cell is a vertical slab electrophoresis instrument which combines versatility with practicality. When used with the various combs, spacers, and accessories available, the PROTEAN II xi cell is suitable for most common electrophoretic techniques, including SDS electrophoresis, two-dimensional (2-D) electrophoresis, native electrophoresis, and agarose gel electrophoresis. The PROTEAN II xi cell can run up to 4 slab gels or 16 tube gels simultaneously. The basic unit accommodates gels 16 or 20 cm long. The 20 cm gels offer increased resolution capability, which is especially useful in 2-D applications.