We examine the science and pedagogy behind a historical approach to the professional development of pre-college science (primarily biology) teachers. Our intention is to reach professional scientists, who, as a group, are uniquely qualified to provide experience and insights essential to this approach. The underlying research for this article has been carried out during an 8-week summer course for selected rural high school science teachers at the Oklahoma Medical Research Foundation in Oklahoma City, Oklahoma. Now configured as part of the broader Oklahoma Science Project, the Summer Course has been held during each of the past 10 years. The result of our experiences is a learning model that incorporates a research dynamic based on peer interactions and Robert K. Merton's concept of specified ignorance. This dynamic is organized around carefully chosen research topics based on simple, quantitative assays that played important roles in the development of our current understanding of genetic chemistry. These assays are starting points for rationally conceived research projects developed by the teachers themselves. We illustrate this approach with the plaque assay for bacterial viruses. (Contains 3 figures and 1 footnote.)