Apparatus for gel electrophoresis with continuous monitoring of individual DNA molecules by video epifluorescence microscopy

Apparatus for gel electrophoresis with continuous scanning by video epifluorescence microscopy was constructed and applied to measurements on individual DNA molecules in the size range of several hundred kilobase pairs. The gel electrophoresis apparatus comprises a horizontal glass cell and several commercially available components—an epifluorescence microscope, an image intensifier, two video cameras, a monitor, videotape recorder and voltmeter. Data in the form of videotapes can be subsequently analyzed on a computer graphics work station.