Born in Brooklyn, New York in 1926, Kirschstein was the daughter of immigrant parents. Her father was a Jewish, Russian chemist who inspired in her an interest in science and a love of music. She received her B.A. magna cum laude from Long Island University in 1947 and her M.D. from Tulane University School of Medicine in 1951.

She researched cancer viruses early in her career, and then live-virus vaccines: polio vaccine, measles vaccine, and rubella vaccine. An authority on infectious neuropathology of monkeys, she received the Department of Health, Education, and Welfare (DHEW) Superior Service Award in 1971 for her contributions in developing monkey safety tests to live viral vaccines and for research on viral oncogenesis.

Dr. Kirschstein became Chief of the Laboratory of Pathology in 1961. She was promoted to Assistant Director of DBS in 1972. When DBS moved administratively to the FDA, Dr. Kirschstein became the Deputy Director of what was then called the Bureau of Biologics.

She was the first woman at NIH to head a NIH Institute. She was the Director of the National Institute of General Medical Sciences (NIGMS) from 1974 until 1993. In 1993 she became acting Director of NIH, the first female to fill this role. In 2000, she again became acting Director.

Dr. Kirschstein worked in Building 29, Rooms 209, 512, and 516 during her time with Biologics.