An award is made to the Washington University in St. Louis to develop a novel wide-field opticalresolution photoacoustic microscope (OR-PAM) and a new high-density single-cell array substrate to achieve simultaneous and high-throughput measurements of single-cell oxygen consumption rates (OCRs) for a large population of cells. OCR is a critical parameter of the functioning of the cells, which is directly linked to their metabolic state. So far, OCR measurements have been performed on bulk populations of cells. Recent studies have shown increasing evidence of cell-to-cell heterogeneity among previously assumed homogeneous populations. Measuring the average response of a cell population to a stimulus may not well reflect individual cell responses. Therefore, conducting OCR measurements on single cells will provide more accurate information on cellular functioning, not only for individual cells but also for the entire cell population. OR-PAM is capable of "label-free" detection of a wide range of biochemicals with high sensitivity and spatial resolution. Combining wide-field OR-PAM with high-density single-cell array substrates will enable high-throughput screening of a large population of single cells in a timely manner for the first time. This project will lay a solid technical foundation for developing a new class of scientific instruments to study heterogeneity in cellular metabolism. These instruments will be accurate, high-resolution, highthroughput, easy-to-use, and low-cost. Therefore, they will significantly impact many areas of biological research. The multidisciplinary nature of this research is expected to offer learning and training opportunities for graduate and undergraduate students to cross their discipline boundaries by learning new principles and methods. Grade 7-12 teachers and students from underrepresented school districts will be involved. Research results will be incorporated into the PIs' course development at both the undergraduate and graduate levels. They will be also disseminated through paper publications and outreach activities to the research community and general public. In addition to the outreach plans, a comprehensive dissemination plan has also been developed. The developed methods, devices and system will be actively promoted to the biological research community through conference presentations, invited talks and seminars. Collaborations and partnerships with bioinstrumentation industries will be established to explore potential opportunities for further development and commercialization.
