The Biophysics Resource (BR) provides access to biophysical instrumentation and any required assistance for researchers from the Center for Cancer Research in need of characterization of systems subject to structural investigations. The BR offers and maintains cutting-edge biophysics technologies in the following areas: - Circular dichroism spectroscopy for studies of optical activity and conformation of biomacromolecules. - Steady-state fluorescence spectroscopy for studies of structure and environment of biomacromolecules and mechanism of their interactions. - Isothermal titration calorimetry for thermodynamic characterization of biomacromolecular interactions. - Liquid chromatography with mass spectrometry detection for macromolecular mass characterization. - Static and dynamic light scattering for determination of macromolecular mass, particle size and degree of aggregation - Microscale thermophoresis for macromolecular binding studies The BR operates as a shared-use facility. Users generally learn to operate the instruments and conduct their own experiments. The BR personnel train researchers wishing to use the facility and they are available to consult on experimental design/analysis or as collaborators in more detailed studies. Also, some equipment is too delicate to permit casual use, e.g. the high-sensitivity calorimeters, and users often collaborate with BR staff in the use of such instrumentation.