The invention relates to the devices analysis field of luminescent particles or optically diffuse.

It relates more particularly to an analysis of a sample of particles in solution, the device comprising a system of microscopy, the microscopy system with means of support that sample, means of illumination able to make a bundle excitation light, ways to focus the beam of excitement at a point of focus at the sample and means of screening to identify suitable space around the focus point of a volume of analysis.