during her graduate school years, she taught hygiene and english at tennessee state college now known as tennessee state university in nashville. in 1940, she became assistant professor of bacteriology at howard university college of medicine. in 1948 she was appointed, and in 1955 she was made head of the department of bacteriology. in 1957, ruth stepped down from her leadership position but continued to teach and conduct research on bacteriology at howard university. in 1960, she was appointed associate professor of microbiology. she retired in 1973 while holding position of the associate professor of emeritus of microbiology until 1990.