That is, make many, many copies of that single molecule that we want to study. In fact, PCR allows us to make millions and billions of these copies from a single individual DNA molecule. So if we synthesize that fragment of DNA by using this solid state method we can then amplify the DNA and produce many, many copies of that DNA molecule. Now, earlier I said that biotechnology can be used in forensic science. For example, let's suppose at some crime scene we find a single follicle of hair. Now, we can extract DNA from that hair follicle and then we can amplify that single DNA strand by using the polymerase chain reaction to produce many of these DNA molecules that we now have at our disposal.