Protocol for isolation and flow cytometric analysis of interstitial macrophages in murine lung metastasis models

Interstitial macrophages increase significantly during lung metastasis and may contribute to tumor dissemination. However, isolating them is challenging due to their localization within lung tissue and phenotypic overlap with other immune cells. Here, we present a protocol for isolating and characterizing murine interstitial macrophages. We include steps for establishing lung metastasis models, lung tissue dissociation, fluorescent antibody staining, and flow cytometry analysis. It is applicable to both metastasized and naive lung tissues. For complete details on the use and execution of this protocol, please refer to Jeong et al.¹.