Michael Heidelberger, an award-winning pioneer in immunochemistry, died June 25 at the age of 103. At the time of his death, he was still a researcher at the New York University Medical Center. Among Heidelberger's many scientific accomplishments was the discovery that antibodies are proteins.
Heidelberger was born in New York and completed his undergraduate and graduate education at Columbia University. After earning his Ph.D. in chemistry in 1911, he joined the faculty of the Rockefeller Institute. In 1928 he returned to Columbia as the first professor of immunochemistry at the university's College of Physicians and Surgeons, where he remained until he was forced to retire in the mid-1950s.
In 1955, in lieu of opting for a life of leisurely retirement, Heidelberger joined Rutgers University in New Brunswick, N.J., as a visiting professor, a position he maintained for the next nine years. In 1964, he joined the NYU Medical Center...