Study of Electrophoretic Mobility of Proteins in Agarose and Poly-Acrylamide Gels

Gel electrophoresis is among the most widely used techniques for separation, characterization, and purification of proteins, nucleic acids, and other molecules including peptides, amino acids, and nucleotides. Electrophoretic measurements can rapidly and reproducibly characterize the size, charge, shape, and purity of these molecules. In this work, we present new measurements of electrophoretic mobility of the protein bovine serum albumin (BSA) in agarose and poly-acrylamide gels, using an optical technique that employs a modified spectrophotometer. The molecular transport rate of BSA due to imposition of a known electric field is investigated in (2-6 %, w/w) agarose gel as well as in (5-15%, w/w) poly-acrylamide gel. By directing the collimated light of the spectrophotometer through a gel/protein matrix, we characterize the molecular motion of the protein under the influence of an applied electric field. We thereby measure the electrophoretic mobility of BSA in agarose gels for the first time, and compare these results directly with the BSA mobility measured in poly-acrylamide gels.This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.