LabBench

Cutting DNA with Restriction Enzymes

You begin by mixing DNA with one or more restriction enzymes in a small plastic microcentrifuge tube. The total volume of the mix is about 20 ľl.

Most restriction enzyme reactions are incubated at 37°C for one hour. After incubation, you can analyze the DNA or use it in other kinds of reactions, such as the bacterial transformation you did in the first part of this lab.

In the next procedure, you will see how to analyze separate DNA fragments with gel electrophoresis.

Microscale Quantities

We use very small quantities when working with DNA, so the volumes and tools are adapted to this microscale. In the metric system, the prefix "micro-" indicates one-millionth. It is symbolized by ľ, the Greek letter mu. Some examples are:

1 ml = 1000 ľl (1000 microlitres)
1 mg = 1000 ľg (1000 micrograms)