Ca2+ Recordings: Hardware and Software (From Microscopes to Cameras)

From an early start, more than two decades ago, Ca²⁺ measurements have evolved from the use of simple systems, built around an epifluorescent microscope, a fluorescent lamp and a photomultiplier, into highly complex set-ups exploiting solid-state light sources and Electron Multiplied cameras to capture in five dimensions with time resolutions from milliseconds to days. In addition to these technological advances, a series of conceptual breakthroughs have enabled microscopy to move well beyond the classical diffraction limit into the realm of optical nanoscopy. Further developments into miniaturization of optical components and advances in optical fibres are bringing Ca²⁺ imaging nearer to intra-vital microscopy applications. In this chapter, we review the basic hardware requirements for Ca²⁺ imaging setups, discuss the latest optical and technological developments and look at the future directions that promise to bring Ca²⁺ imaging to a more central place in the medicine of the future.