[4] He joined the University of California, Berkeley as a faculty member in 1956, where he was professor in the graduate school and a faculty senior scientist, physical biosciences division, Lawrence Berkeley National Laboratory.
[5] He is known for his pioneering work on RNA folding and the secondary structures of ribonucleic acid.
[6][7][8] His graduate and postdoctoral students include Carlos Bustamante and Frances Arnold.
[6] His honors and awards include: Guggenheim Fellow, Medical Research Council Laboratory, Cambridge (1964); California Section Award, American Chemical Society (1965); D.Sc.
University of New Mexico (1972); Member, National Academy of Sciences (1985); Elisabeth R. Cole Award (Founders Award), Biophysical Society (1996);[9] Berkeley Citation, University of California (1996); Member, American Academy of Arts and Sciences (2001); Emily M. Gray Award, Biophysical Society (2006); Fellow: American Physical Society, Biophysical Society.