The proposed purchase of an SLM 48000S Multifrequency Phase Fluorometer, together with a Coherent Innova 90-5 UV Argon Ion Laser, will be used to implement advanced fluorescence spectroscopy capabilities in the Biochemistry Division, Department of Chemistry and Biochemistry, University of Colorado. Topics of major study will include the following. - Structure and function of catalytic RNAs. - DNA bending. - Structural dynamics of sensory proteins. - Metal binding to Ca(II) binding proteins. - Substrate binding to oxygen carrier proteins. - Structure and dynamics of antimicrobial peptides from human neutrophils. - Solvent effects on the energetics and dynamics of organic and biochemical reactions. The demand within the Division for advanced fluorescence instrumentation is increasing due to the growth of research projects focusing on novel structural, mechanistic and dynamic features of nucleic acids and proteins; the addition of new faculty members; the development of new methods for covalent modification of nucleic acids with fluorophores; and the obsolescence of our existing instrumentation.