The long-term objective of the Scientific Core is to provide state-of-the-art Core facilities that support each of the four projects of the Program. Core B is composed of a Phosphorimager facility and a protein expression and purification facility, as well as other shared facilities including a dark room and liquid nitrogen freezers. The Phosphorimager will be used for imaging and quantification of various results including primer-extension assays, gel mobility shifts, and Western blots. The protein expression and purification facility consists of a shaking incubator, a centrifuge, an FPLC, and protein expression vectors. It is used to express and purify proteins that are studied in each of the projects. The Scientific Core also possesses liquid nitrogen freezers for the storage of cell lines and a gel documentation system. In addition, expertise is provided to all member laboratories by personnel who oversee the Core. This Scientific Core is essential to the success of the Program, and serves to facilitate interaction between member laboratories.