A simple method to assay the major properties of DNA polymerases such as template binding, polymerase and exonuclease activities in one step is exemplified with the DNA polymerases of E. coli, bacteriophage T4 and herpes simplex virus. Combining the advantages of the band-shift assay with the resolving power of polyacrylamide gradient gel electrophoresis, the procedure is particularly useful for a rapid functional analysis of mutant polymerases as well as inhibitors of DNA replication.
