In vivo optical molecular imaging and analysis in mice using dorsal window chamber models applied to hypoxia, vasculature and fluorescent reporters

Optical techniques for functional imaging in mice have a number of key advantages over other common imaging modalities such as magnetic resonance imaging, positron emission tomography or computed tomography, including high resolution, low cost and an extensive library of available contrast agents and reporter genes. A major challenge to such work is the limited penetration depth imposed by tissue turbidity. We describe a window chamber technique by which these limitations can be avoided. This facilitates the study of a wide range of processes, with potential endpoints including longitudinal gene expression, vascular remodeling and angiogenesis, and tumor growth and invasion. We further describe several quantitative imaging and analysis techniques for characterizing in vivo fluorescence properties and functional endpoints, including vascular morphology and oxygenation. The procedure takes similar to 2 h to complete, plus up to several weeks for tumor growth and treatment procedures.