Tumor Angiogenesis Assays

Ann L. B. Seynhaeve, Timo L. M. ten Hagen

Real-time evaluation of vascular effects in an animal skinfold window model by intravital microscopy (IVM) provides a powerful tool to improve insight into vascular development and vascular therapy. The potential of IVM to examine processes in tissues (e.g., tumors, inflammatory sites), in a noninvasive way, enables determination of the kinetics of processes under study at any given time point. The introduction of sensitive digital cameras, confocal and multiphoton microscopy, and powerful imaging software greatly improved the quality of the images acquired. Together with the introduction of better fluorescent probes, with a shift towards red and near-infrared fluorescence, confocal and multiphoton microscopy enables deeper imaging with less (photo)toxicity. IVM is particularly useful for examination of processes in time, which span seconds up to days or even weeks, such as tumor vascular development. Here we describe an advanced dorsal skinfold window chamber for high-resolution intravital microscopy of tumor angiogenesis.