Fast quantitative assay of sequence-specific endonuclease activity based on DNA sequencer technology.

A quantitative assay of the sequence-specific endonuclease activity of Vsr DNA mismatch endonuclease is described. The procedure rests on fluorescently labelled oligonucleotide substrates and an automated DNA sequencer to determine amounts of both educt and product of the reaction; thus each individual measurement is internally standardized. The assay achieves high sample throughput by parallel measurement of multiple samples. Because of its capacity to produce and process large sets of experimental data, the system is particularly well suited for the determination of reaction kinetics. The procedure lends itself to further simplification by implementing software additions for direct peak integration. Obviously, the principle of the assay can be extended to the study of other enzymes, such as restriction endonucleases or sequence-specific proteases.