Two-photon photolysis combined with a kilobeam array scanner to probe calcium signaling in cardiomyocytes

Photorelease of caged compounds allows a fast and defined intracellular increase in calcium (Ca(2+)) or other biologically relevant substances or molecules without impinging on other cellular functions. In particular, two-photon photolysis (2PP) allows a spatially restricted uncaging in sub-femtoliter volumes. Here, we describe how to combine 2PP with a confocal kilobeam array scanner and provide an example where Ca(2+) is released in an isolated cardiac myocyte.