A DNA-acrylamide gel column for analyzing proteins that bind to DNA. I. DNA polymerase

A new procedure is described for purifying proteins that specifically bind to DNA. DNA is entrapped in polyacrylamide gel particles which can then be used in standard column chromatographic procedures. The method was developed using Escherichia coli DNA polymerase as the test material. The crude enzyme was applied at low ionic strength and eluted at high ionic strength with a 200-fold increase in specific activity on a single passage through the column. The method is versatile and simple and is not restricted to DNA-protein systems. Any macromolecule can be entrapped in the gel particles; these can interact with other large or small molecules in the liquid phase. The gel is stable at elevated temperatures and can therefore be used in hybridization experiments.