This project involves the acquisition of a phosphoimager system for molecular biology research and training. The instrument will be housed in the Department of Biology at Indiana University-Purdue University at Indianapolis and will serve 5 major and two minor users in the department of Biology and two major users in the Department of Chemistry. All major and minor users employ conventional autoradiography, fluorography and/or chemiluminescent detection with film on a routine basis. However, these techniques are limited by the narrow linear response range of film and by the lengthy exposure times required for the fluorographic detection of weak energy isotopes such as 3H and 14C. Phosphoimager analysis has several key advantages over autoradiography and fluorography. First, phosphoimager screens have a linear response range of five orders of magnitude as opposed to only two for autoradiography. Second, phosphoimager exposure times are generally only one tenth those required for autoradiography and fluorography. This is especially advantageous for the detection of weak energy isotopes where fluorography exposure times of weeks or months are often required. Third, the phosphoimager data can be quantified and imported into computer drawing programs for accurate quantitative analysis. This system will complement existing molecular biology equipment in the laboratories of the major and minor users. Moreover, the high degree of accuracy and efficiency afforded by phosphoimager analysis will improve the quality and quantity of molecular biology research and teaching performed by the investigators.