A Beckman Optima XL-A analytical ultracentrifuge will be purchased for use in multidisciplinary research in the Biochemistry and Chemistry Departments at Louisiana State University. The ultracentrifuge will be used to characterize peptides, rodlike synthetic polymers, proteins, and nucleic acids. Molecular weights, aggregation states, and mutual friction coefficients of these molecules will be determined. This information will be used in studies of the mechanism of action of lytic peptides, transport in semidilute solutions, protein structure and stability, and DNA dynamics.