Harold Joel Conn

Harold Joel Conn (May 29, 1886 – November 10, 1975) His parents were the bacteriologist Herbert William Conn (1859–1917), one of the founders of the Society of American Bacteriologists, He had one sister, Bertha. Conn started to experience progressive hearing loss as a child of 12; he describes his father as having encouraged him to overcome the challenges posed by his deafness. Conn showed that soil bacteria can sometimes increase when the soil is frozen; the counterintuitive result led to considerable discussion in the scientific community. In November 1921, he founded the precursor to the American Biological Stain Commission with Rolland T. Will, C. E. McClung, S. I. Kornhauser and L. W. Sharp, and served as one of its founding executive committee members and later its chairman. The commission tested bacteriological and histochemical stains from the fledgling American dye industry, brought into existence by the problems in acquiring stains from Germany after the First World War. From 1922, Conn supervised thirty assistants at the Agricultural Experiment Station in this work. and also chaired the society's techniques committee.

He also published several texts on staining including Biological Stains (1925), History of Staining (1933; 1948) and Staining Procedures (1944–55; 1960). According to the Biological Stain Commission, Biological Stains "has become a standard source of reference in technical and research histopathological and biological laboratories using dyes" and was brought out in a tenth edition in 2002.

Personal life Conn's hearing loss was progressive throughout his life. Deafness significantly impaired his ability to communicate face to face with other scientists. He was little helped by hearing aids, and also had difficulties with lip reading. Conn's wife died in 1963. Conn died in Geneva, New York, in 1975, aged 89.