James Freyer is a Biophysicist with 45 years of experience in flow cytometry, biomedical optics and multicellular tumor spheroids. Jim’s career started at the Bioscience Division of the Los Alamos National Laboratory, where he developed long-term projects in spheroid biology and biomedical optics and served as Director of the NIH-funded National Flow Cytometry Resource. Dr. Freyer then moved to the Center for Biomedical Engineering at the University of New Mexico, teaching and developing novel in vitro tumor model systems. Continuing his focus on instrumentation and spheroid assay development, Jim co-founded BennuBio Inc., a small business developing instrumentation for rapid imaging and analysis of intact multicellular structures. This technology has fulfilled a long-term dream of developing flow cytometry instrumentation and assays for the rapid analysis of intact spheroids. Dr. Freyer also has a long connection to this course as a lecturer and lab instructor, as well as serving as Director of the course for many years. Along with spending time with his four granddaughters, Jim enjoys skiing, hiking, kayaking, camping, wood working, beer making and (lately) replacing worn-out body parts so he can continue with those things.