After earning his Ph.D. in 1927 from MIT, Proctor went to work as an instructor in the biology and public health department at the Institute.
During his career at MIT, Proctor worked on the application of food irradiation with Samuel A. Goldblith and Daniel F. Farkas, both of whom were graduate students under Proctor at MIT. Goldblith would later work with Proctor on the MIT faculty until Proctor's 1959 death.