Protocol for sub-mucosal orthotopic injection of organoids into murine colon to study tumor growth and metastasis.

Orthotopic mouse models of colorectal cancer (CRC) better recapitulate the physiological processes of tumor development and metastatic dissemination. Here, we provide a protocol for colonoscopy-guided transplantation of organoids into the murine colon. We describe the steps for preparing mouse organoids, equipment, and mice for injections, as well as performing colonoscopy-guided mucosal injections and providing subsequent care. This model can be used to investigate various experimental setups, including survival, metastatic potential, and the effects of treatments. For complete details on the use and execution of this protocol, please refer to Felchle et al..