Uniform-intensity, visible light source for in situ imaging.

A flexible, low-cost, high-brightness light source for biological and biomedical imaging is presented. The illuminating device consists of a custom-size square plastic pouch 10 to 20 mm on a side and 1 to 3 mm thick that can be inserted fully or partially into both in situ or in vitro specimens to be imaged. The pouch contains a silicone-based gel medium embedded with silica particles that scatters light and provides a reasonably uniform, planar light source.