SDS Agarose Gels for Analysis of Proteins

A new agarose-based protein electrophoresis gel system is described. The system consists of a highly resolving agarose, MetaPhor XR (FMC BioProducts, Rockland, ME, USA) dissolved in urea and TBE buffer and a stacking gel composed of a high gel-strength agarose, SeaKem Gold (FMC BioProducts). TBE containing sodium dodecyl sulfate (SDS) is used as electrophoresis buffer. The disadvantages of traditional agarose gels have been overcome, and several advantages over polyacrylamide gels have been demonstrated. The system is capable of high-resolution separation of small proteins and has a dynamic separation range equivalent to a 4%-20% gradient polyacrylamide gel. Furthermore, the staining of protein bands by Coomassie Brilliant Blue is very uniform in this gel, and depending on the protein, higher detection sensitivity can be obtained compared to SDS polyacrylamide gels. In Western blotting, proteins are more efficiently transferred to the membrane from the agarose gel than from polyacrylamide gels. Finally, the exceptional stability of agarose allows for gels to be precast and stored for a year.