University of Illinois Cancer Center 1 article published in JoVE Bioengineering Handling and Assessment of Human Primary Prostate Organoid Culture Tara McCray*1, Zachary Richards*1, Joseph Marsili1, Gail S. Prins1,2,3, Larisa Nonn1,3 1Department of Pathology, University of Illinois at Chicago, 2Departments of Urology, Physiology, and Biophysics, University of Illinois at Chicago, 3University of Illinois Cancer Center Here, we present a protocol to guide human primary prostate organoid handling then suggest endpoints to assess phenotype. Seeding, culture maintenance, recovery from matrix gel, morphologic quantification, embedding and sectioning, FFPE sectioning, whole-mount staining, and application of commercial assays are described.