Elizabeth Lee Hazen (August 24, 1885 - June 24, 1975) was an American microbiologist. In 1927 she completed her Ph.D. in microbiology, one their first female doctoral students. In 1948, she teamed up with Brown to develop nystatin, the first non-toxic drug treatment for fungal infections in humans. She died in 1975 at the age of 89. Rachel Fuller Brown (November 23, 1898 - January 14, 1980) was an American chemist. Due to the depletion of her savings, she was forced to leave Chicago without her Ph.D to find a job at the Division of Labor and Research in Albany, New York. She focused on identifying the types of bacteria that caused pneumonia, helping develop a pneumonia vaccine still in use today. In 1948 she began her work with Hazen. In 1951, the Department of Health and Laboratories promoted Brown to associate biochemist. Brown and Hazen, in continuing their research, discovered two additional antibiotics - phalmycin and capacidin. The two continued to work closely together in making additional minor contributions to the field of bacteriology until their retirement. Brown died in 1980 at the age of 81.