1. A method of rotational scanning of fluorescent light emitted from fluid samples: placing fluid samples in at least one sample holder in a rotating carousel that is simultaneously moved in a linear direction, the fluid samples having fluorescent light emitting target substances; scanning the fluid samples with low resolution R-theta scans of a beam spot with a confocal microscope arrangement detecting levels of emitted fluorescent light, including background bulk fluorescence collected by the confocal microscope arrangement at locations that define emitted fluorescent light volumes of interest exceeding background bulk fluorescence emission; mapping fluorescent volumes of interest of the low resolution scans in planes having fluorescent signals with specified concentrated emission; and then probing the planes having mapped fluorescent volumes of interest within said planes with a confocal microscope high resolution manner to establish fluorescent light emitting target substances exceeding the background bulk fluorescence emission.