Autoradiography: high-resolution molecular imaging in pharmaceutical discovery and development

Autoradiography (ARG) is a powerful, high resolution, quantitative molecular imaging technique used to study the tissue distribution of radiolabeled xenobiotics in biologic models. ARG involves the close apposition of solid specimens containing a radiolabeled substance to a detector layer, such as photographic emulsions, film, phosphor imaging plates and direct nuclear imagers/counters. The two basic types include: macroautoradiography, which is imaging of organs, organ systems and/or whole-body sections (WBA) and microautoradiography (MARG), which provides the localization of radioactivity at the cellular level. ARG has supported drug discovery and development efforts for many years and has provided pivotal decision making information for pharmaceutical research. This paper presents a review of the techniques, study designs and present considerations for use of WBA and MARG to support today's drug discovery and development efforts. In addition, this review comments on the integration of the ex vivo ARG and in vivo molecular imaging techniques to serve pharmaceutical discovery and development in the future.