Control of restriction enzyme activity by local concentration of magnesium ion

Observation and cutting of DNA molecules at arbitrary positions permit several new experimental methods that are completely different from conventional methods of molecular biology, therefore several cutting methods have been proposed and studied. In this report, a new cutting method for a DNA molecule by localizing the activity of restriction enzyme is presented. Since most restriction enzyme requires magnesium ion for their activation, the local restriction enzyme activity can be controlled by the local concentration of magnesium ions. The local concentration of magnesium ions can be controlled electrochemically by applying a DC voltage to a needle electrode of magnesium metal. The restriction enzyme can be activated only when magnesium ion is electrochemically supplied.