How are the worlds of university biology and commerce blurring? Many university leaders see the amalgamation of academic and commercial cultures as crucial to the future vitality of higher education in the United States. In Impure Cultures, Daniel Lee Kleinman questions the effect of this blending on the character of academic science. Using data he gathered as an ethnographic observer in a plant pathology lab at the University of Wisconsin - Madison, Kleinman examines the infinite and inescapable influence of the commercial world on biology in academia today. Contrary to much of the existing literature and common policy practices, he argues that the direct and explicit relations between university scientists and industrial concerns are not the gravest threat to academic research. Rather, Kleinman points to the less direct, but more deeply-rooted effects of commercial factors on the practice of university biology. He shows that to truly understand research done at universities today, it is first necessary to explore the systematic, pervasive, and indirect effects of the commercial world on contemporary academic practice.