This project will be an effort to establish the feasibility of a new instrumental approach to the rapid determination of the spatial distribution of radio-labeled fragments of DNA in electrophoresis gels. The instrument system concept is that of a single-event- counting two-dimensional scintillation detector that provides digitized position and amplitude data for beta-rays and X-rays emitted by a gel for display and analysis by a computer. It is expected that the feasibility of such an instrument will be established by means of analytical and experimental studies which will result in a set of performance parameters and a comparison of component requirements with commercially available components as a basis for a further development effort.