Protocol for ultrasound-guided injection into the murine portal vein to initiate liver metastasis.

Here, we present a non-surgical protocol for modeling murine liver metastasis by disseminating injected cells or compounds into the murine portal vein. We describe steps for identifying the portal vein and other vital structures adjacent to and within the liver by ultrasound, determining an optimal route to avoid vital structures, and injecting into the portal vein. We also report on the findings for reproducibility, adverse effects, and histopathological findings.