The invention relates to a method for identifying a variant of a biomolecule among a plurality of variants of the biomolecule by these steps: A) Acquiring a fluorescence intermittence signal pattern for each variant. Each of the variants is labelled with a blinking fluorophore. B) Determining a fluorescence intermittency signal characteristic for each variant. C) Labelling at least one variant of the biomolecule in a sample with the fluorophore, and acquiring its fluorescence intermittency signal. D) Determining a presence of at least one fluorescence intermittency signal characteristic as determined in step B) in the acquired fluorescence intermittency signals from the sample. E) Establishing the presence, the quantity and/or localisation, of at least one variant of the biomolecule in the sample based on the fluorescence intermittency signal characteristic.