Establishment and validation of an orthotopic brain metastasis tumor model in C57BL/6 mice

As a key experimental method to study the pathogenesis of brain tumors, the establishment of standardized operation process for intracranial orthotopic tumor modeling is of great significance. At present, although this technology has become the main method for brain tumor research, it has been reported in the literature that there is significant heterogeneity in the injection sites, and there is a lack of systematic verification, which leads to the repeatability of the experiment being questioned. In view of this technical bottleneck, this study used female C57BL mice as a model to establish a standardized intracranial tumor formation operation system. By systematically analyzing the two anatomical markers of bregma and lambda in mice, we not only clarified the quantitative relationship between body weight and bregma-lambda distance in C57BL mice, but also defined the normal range of bregma-lambda distance. More importantly, we found and verified a new standardized injection site. Based on this finding, this study finally constructed a complete set of intracranial tumor formation technology scheme including positioning method, operation specification and quality control.