The recent advances in electrophoresis technology have opened up the possibility for the development of new, high performance instrumentation in biologicl research. One such technology, capillary electrophoresis (CE), provides much greater resolution than traditional gels and run speeds as much as an order of magnitude faster traditional separation techniques. Perhaps its greatest virtue is that the technique is quite amenable to the incorporation of on-line detection systems and the development of automated instrumentation. The Contractor's SBIR Phase I program addressed the particular need for an on-line radioactivity detector system which allow CE to be used in DNA research. The prototype detector built in Phase I was constructed from a small cadmium telluride (CdTe) solid-state nuclear radiation sensor and was found to provide 83% detection efficiency for 32p and a spatial resolution of 1.25 mm. Therefore, these new sensors are well-suited for on-line detection of radiolabeled DNA. In Phase II, the Contractor shall use multielement arrays of these detectors in the development of a new CE instrument - an automated restriction fragment analyzer. This approach will make it possible to utilize the high resolution and speed of CE with on-line detection of radioactive DNA fragments to aid in the construction of DNA restriction site maps.