Optical mapping is a promising alternative for fast, simple, and affordable analysis of single DNA molecules. Watch the video to observe an optical mapping experiment, where whole molecules or fragments of DNA are driven through nanochannels by electrophoresis. Since DNA has a net charge, it is driven into the nanochannels to pass from one microchannel to the other. Inside the nanochannels, the DNA molecules are uncoiled and elongated, which enables the optical mapping measurement. The master st