Patent ID: 8174692

Claim:
A method for high spatial resolution imaging of a structure of interest in a specimen, having the steps: selecting a substance from a group of substances, which have a first electronic state in which they can be excited by light of one wavelength to spontaneously emit fluorescent light, which can be converted from their first electronic state into a second electronic state by the light of the one wavelength, which can not be excited by the light of the one wavelength to spontaneously emit fluorescent light in their second electronic state, and which can return from their second electronic state into their first electronic state; marking the specimen's structure of interest with molecules of the substance; imaging the specimen onto a sensor array, a spatial resolution limit of the imaging being greater than an average spacing between closest neighboring molecules of the substance in the specimen; exposing the specimen to the light of the one wavelength in at least one region which has dimensions larger than the spatial resolution limit of the imaging of the specimen onto the sensor array at such an intensity that changing fractions of the molecules of the substance being in their first electronic state are, by the light of the one wavelength, excited to spontaneously emit fluorescent light and converted into their second electronic state, and that at least 10% of the molecules of the substance that are respectively in the first electronic state lie at a distance from their closest neighboring molecules in the first state which is greater than the spatial resolution limit of the imaging of the specimen onto the sensor array; registering the fluorescent light which is spontaneously emitted by the molecules of the substance in the region, in a plurality of images recorded by the sensor array during continued exposure of the specimen to the light of the one wavelength; and determining the position in the specimen of the molecules of the substance that are respectively in the first electronic state, which lie at a distance from their closest neighboring molecules in the first electronic state which is greater than the spatial resolution limit of the imaging of the specimen onto the sensor array, from the images recorded by the sensor array.