Postdoctoral Fellow, Medical Research Council Laboratory, Cambridge, England. 1970 - 73. Research with David Blow.
Asst. Professor, Department of Chemistry and Biochemistry, Univ. Calif. Los Angeles, 1973 - 83.
Biophysicist, Department of Biology, Biosciences, and National Synchrotron Light Source II, Brookhaven National Laboratory, 1983 - Present.