Simple and Robust Intravital Microscopy Procedures in Hybrid TIE2GFP-BALB/c Transgenic Mice.

Purpose: The endeavor of deciphering intricate phenomena within the field of molecular medicine dictates the necessity to investigate tumor/disease microenvironment real-time on cellular level. We, hereby, design simple and robust intravital microscopy strategies, which can be used to elucidate cellular or molecular interactions in a fluorescent mouse model.

Procedures: We crossbred transgenic TIE2GFP mice with nude BALB/c mice, allowing the breeding of immunocompetent and immunodeficient mouse models expressing green fluorescent protein (GFP) in vascular endothelium. Then, we surgically exposed various tissues of interest to perform intravital microscopy.

Results: By utilizing simple tissue preparation procedures and confocal or two-photon microscopy, we produced high-resolution static snapshots, dynamic sequences, and 3D reconstructions of orthotopically grown mammary tumor, skin inflammation, brain, and muscle. The homogenous detection of GFP expressed by endothelial cells and a combination of fluorescence agents enabled landmarking of tumor microenvironment and precise molecular tagging.

Conclusion: Simple intravital microscopy procedures on TIE2GFP mice allowed a real-time multi-color visualization of tissue microenvironment, underlining that robust microscopy strategies are relatively simple and can be readily available for many tissues of interest.