 Currently, Johnson's research investigates the history of the reproductive and developmental sciences and their historical relationship to the development of human "In vitro" fertilisation and other clinical technologies, and to their regulation legally and ethically.Johnson collaborates with Kay Elder, at the Bourn Hall Clinic, Sarah Franklin and Nick Hopwood in the Department of History and Philosophy of Science, University of Cambridge.Johnson has co-authored over 300 papers on reproductive and developmental science, history, ethics, law and medical education.