Beckman Optima A/I Analytical Ultracentrifuge (AUC) - PROJECT SUMMARY Characterizing the sizes, shapes, and interactions of biomolecules is a crucial prerequisite to understanding biological function on a molecular level. Analytical ultracentrifugation (AUC) has been an essential component of the biophysical tool kit for decades, exploiting the distinct optical and sedimentation properties of proteins, nucleic acids, and polysaccharides to provide information on molecular structure and its changes. For example, changes in the stoichiometry of a multimeric protein caused by small molecule binding, or the addition of a partner protein, can be quickly and accurately quantified by changes in sedimentation properties. AUC measurements are made in a matrix-free solution, typically without the need for exogenous labels, more accurately capturing biological context than many other techniques commonly used to measure binding. AUC analysis does not destroy nor dilute precious samples, making them fully recoverable for additional downstream analyses. Over the past two decades, major advancements in AUC design now enable more rapid detection of more complex molecular assemblies using a large number of wavelengths for absorbance measurements. This proposal, in response to Program Announcement PAR-22-081, requests funds to purchase a state-of-the-art Beckman Coulter Optima A/I AUC to advance the research goals of University of Notre Dame’s NIH-funded scientists and engineers. This instrument will replace Notre Dame’s current Beckman Coulter ProteomeLab XL-I AUC, the only AUC broadly available within a 90-mile radius of Notre Dame. Despite careful maintenance and support over its lifetime at Notre Dame, the ProteomeLab AUC has been plagued by numerous malfunctions over the past year. Crucially, the ProteomeLab AUC will no longer be eligible for Beckman service support after 2025 and, at 18 years old, is optically and mechanically inadequate to modern instruments. The new AUC will be housed in a recently renovated and expanded core facility; its acquisition is an important piece of a large effort currently underway to expand and improve research infrastructure at the University of Notre Dame. As such, supervision, care, and maintenance of this instrument will contribute to employment stability for core facility staff, while access to this state-of-the-art research equipment will continue to grow the scope and scale of research at Notre Dame.
