The origin and the development of scientific disciplines has been a topic of reflection for several decades. The few extensive case studies support the thesis that scientific disciplines are not monolithic structures but can be characterized by distinct social, organizational and scientific-technical practices. Nonetheless, most disciplinary histories of genetics confine themselves largely to an uncontested account of the content of the discipline or occasionally institutional factors. Little attention is paid to the large number of researchers who, by their joint efforts, ultimately shaped the discipline. We contribute to this aspect of disciplinary historiography by discussing the role of women researchers at the Institute for Heredity Research, founded in 1914 in Berlin under the directorship of Erwin Baur, and the sister of the John Innes Institute at Cambridge. This paper investigates how and why Baur built a highly successful research programme that relied on the efforts of his female staff, whose careers, notably Elisabeth Schiemann's, are also assessed in toto. These women undertook the necessary 'technoscience' and in some cases innovative work and helped increase the prestige of the institute and its director. Together they played a pivotal role in the establishment of genetics in Germany. Without them the discipline would have developed much more slowly and along a divergent path.