Electrophoretic extraction-concentration of proteins from polyacrylamide gels under alkaline, neutral and acidic conditions
Morinaga Institute of Biological Science, Yokohama A simple technique has been developed for the electrophoretic extraction of milligram to microgram quantities of protein, under constant monitoring by dye line, in a concentrated form from polyacrylamide gels run under alkaline, neutral and acidic conditions. Typically, the extraction time from 5 gel slices per tube containing about 1.2 mg of bovine serum albumin or a-chymotrypsinogen A was 3 h, and the maximum concentration of the recovered protein was 5 mg/rnl with a total recovery of more than 90 % in all cases. Higher protein concentrations (1 1 mg/ml) could be obtained by increasing the extraction time to 3.5 h or by using resins like glass beads. The alkaline extraction system has been applied to the purification of glutamyl-tRNA synthetase up to homogeneity, and also to ferritin. This technique can also be usedunder reducing conditions and the scale of operation can be adjusted by the number of tubes or number of slices.