Frank Henry Joseph worked as an assistant in the Bacteriology Laboratory of Guy's Hospital, London, from 1896. In February 1903 he was appointed as assistant bacteriologist in the Government Laboratory of the Transvaal Colony, Johannesburg, under the government analyst and bacteriologist W.C.C. Pakes*, who had requested his appointment. The next year, at the annual congress of the South African Association for the Advancement of Science held in Johannesburg, he delivered "Notes on some pathogenic bacteria as found in the Transvaal and the variations from their European prototypes". The paper was published in the association's Report of the meeting (pp. 237-242). At the 1907 congress he read a note on "Bacillus Anthracoides in Transvaal water supplies" (Report, p. 127). Most of his work was, however, of a routine nature. He remained a member of the association for a few years only.
Upon the formation of the Union of South Africa in 1910 Joseph was retained in his post as first grade bacteriological assistant in the Government Laboratory. A few years later he was seconded as senior bacteriological assistant to the newly established South African Institute for Medical Research in Johannesburg. Soon thereafter, around 1915, he was appointed business manager of the institute's Routine Division. In 1917 he was demoted for failing to test the sterility of a batch of typhoid vaccine, resulting in two deaths. He resigned from his post in 1919.