German Cancer Consortium (DKTK), Partner site Munich (LMU), a partnership between the German Cancer Research Center (DKFZ) and the University Hospital of LMU Munich 1 article published in JoVE Cancer Research Strategy for Biobanking of Ovarian Cancer Organoids: Addressing the Interpatient Heterogeneity across Histological Subtypes and Disease Stages Fabian Trillsch*1,2, Juliane Reichenbach*1, Bastian Czogalla1, Fabian Kraus1, Alexander Burges1, Sven Mahner1,2, Mirjana Kessler1,2 1Department of Obstetrics and Gynecology, University Hospital, Ludwig-Maximilian-University (LMU) Munich, 2German Cancer Consortium (DKTK), Partner site Munich (LMU), a partnership between the German Cancer Research Center (DKFZ) and the University Hospital of LMU Munich This protocol offers a systematic framework for the establishment of ovarian cancer organoids from different disease stages and addresses the challenges of patient-specific variability to increase yield and enable robust long-term expansion for subsequent applications. It includes detailed steps for tissue processing, seeding, adjusting media requirements, and immunofluorescence staining.