PROJECT SUMMARY/ABSTRACT The Flow Cytometry Shared Resource (FCSR, formerly called the Optical Biology Shared Resource or Opticore) provides access to state-of-the-art flow and tissue cytometry, cell sorting, and single cell genotyping and qPCR for the UC Davis Cancer Center community. Flow Cytometry Shared Resource equipment and personnel are available at two locations: one at the Davis campus (Tupper Hall) and one on the Sacramento campus (Institute for Regenerative Cures). The FCSR is led by Ms. Bridget McLaughlin (Technical Director), and Mr. Jonathan Van Dyke (Technical Manager), with faculty oversight from Dr. Barbara Shacklett (Scientific Director), and a 13-member Scientific Advisory Committee. The Specific Aims of the FCSR shared resource are to: provide state-of-the-art cell sorting and analytical cytometry; provide consultation about appropriate experimental design and data analysis; provide education about routine as well as cutting-edge cytometry applications; facilitate interactions among researchers using these techniques; and stimulate development of new approaches for cancer research. FCSR staff members provide Cancer Center investigators with training in experimental design, operation of instruments, and analysis of data. Cell sorting services are provided by technical staff, but the goal is to have other instruments (i.e., analytical cytometers and the qPCR analyzer) operated by researchers whenever possible. In addition to individualized training for users, the FCSR offers an annual, week-long flow cytometry course during the summer in partnership with the UC Davis Biotechnology Program. Finally, the FCSR develops collaborations with leading investigators in flow cytometry nationwide to bring developing technology and new applications to UC Davis. In the past 5 years the FCSR assisted a total 193 Investigators; of those, 103 are Cancer Center members. The FCSR serves all Cancer Center Programs; the programs in Molecular Oncology, Comparative Oncology and Cancer Therapeutics have the largest number of FCSR users (>25 per program). Notable accomplishments in the past five years include the awarding of an NIH S10 instrumentation grant to purchase a new high-speed cell sorter (2015); award of an S10 grant to purchase a Fluidigm BioMark single cell gene analysis platform (2013); and award of an S10 grant to purchase a BD Fortessa analytical cytometer (2010).