The invention relates to a method for examining different structures in preferably biological preparations in a differential manner, especially by means of confocal laser scanning microscopy. The method is characterized in that particles having a specific diameter and specific characteristics are assigned to the structures and in that said structures are detected by detecting the particles which have specifically bonded in or to the preparations. The detection process is carried out in an advantageous manner by marking the structures with metal particles with diameters of 10 nm to 1,500 nm and detecting Mie scattering or a plasmon signal.