This procedure is a quick check of the optical hardware and evaluates the overall system performance. It takes typically a few minutes and allows the overall alignment to be easily maintained. We recommend to do it at least once a week, prior to every new measurement session, or after changing a key element of the optical layout, for example the major dichroic, or changing the excitation wavelength or the microscope objective. The basic idea is to just follow the excitation beam path step by step from the Laser Combining Unit (LCU) to the sample, back to the video camera as well as to the basic confocal unit and finally to the detectors.