Method and apparatus for highly spatially resolved imaging a labeled with a fluorescent dye structure

A method for high spatial resolution imaging of a labeled with a fluorescent dye structure, wherein the fluorescent dye is repeatedly excited within a range with excitation light to emit fluorescent light by being transferred from a ground state to an excited fluorescent state, and wherein fluorescent light from the area is registered, to determine a three-dimensional concentration distribution of the fluorescent dye, wherein the fluorescent dye in the field is applied with an optical signal from a repetition of its excitation, whereby a ratio of a yield of fluorescent light to the concentration of the fluorescent dye in the region during the subsequent excitation of the fluorescent dye increases is characterized in that the optical signal (10) has a different wavelength than the excitation light (6) and the ratio of the yield stabilized at a value against BER is increased one without the optical signal falling value, and that the structure during repeated Anregens with the excitation light (6) at a reduced temperature of less than 0 ...