The Scientific Core exists to facilitate the scientific projects within the program. The services, materials and reagents provided by the Scientific Core are purified proteins from natural and recombinant sources and infectious prions, synthetic peptides, DNA sequencing, PrP antibodies, transgenic mouse screening and a chemical and biochemical analytical service. This core will be directed by Drs. Michael Baldwin and Giuseppe Legname. Dr. Baldwin, an Adjunct Professor, is an analytical chemist with extensive experience of working with peptides and proteins, and has been associated with Dr. Prusiner's prion research group for 14 years. Dr. Legname has been at UCSF for 4 years and is an Assistant Adjunct Professor with expertise in molecular biology, immunology, protein expression and biochemistry. They are already directing the Scientific Cores of other program grants in Dr. Prusiner's laboratory. Dr Giuseppe Legname will direct the preparation of recombinant PrP variants and recombinant antibodies that will be expressed in cell cultures and purified for use in the various projects, assisted by Mr. Patrick Culhane. The preparation of purified prions has been carried out in this laboratory for many years and for more than a decade has been supervised by Ms. Hana Serban, recently with assistance from Ms. Nadia Kovaleeva. The purification of infectious prions will be essential for Project 1. Ms. Serban will also supervise the production of PrP antibodies required for Projects 3 and 4 and Core C. The screening of the transgenic mice is essential for Projects 3 and 4 and will be carried by Ms. He-Ying Lin under the supervision of Dr Kurt Giles, Assistant Adjunct Professor. Peptide synthesis will be conducted by a newly appointed Assistant Adjunct Professor, who will also assist Dr. Baldwin with chemical and biochemical analysis, which will benefit all the projects. All of these activities are currently being carried out very successfully in this laboratory through the efforts of the highly experienced personnel referred to above.