Patent ID: 7626703

Claim:
A method comprising: providing spatially-structured activation radiation having relatively high intensity regions and relatively low intensity regions to a sample that includes phototransformable optical labels (“PTOLs”) to activate a subset of the PTOLs in the sample located predominately at relatively high intensity regions of the spatially-structured activation radiation; providing spatially-structured excitation radiation to the subset of activated PTOLs in the sample, wherein the excitation radiation is structured so that one or more relatively high intensity regions of the excitation radiation at least partially overlap one or more relatively high intensity regions of the activating radiation and to excite PTOLs located at the relatively high intensity regions of the excitation radiation; detecting radiation emitted from the activated and excited PTOLs with imaging optics; and controlling the intensities and spatial structures of the activating radiation and the excitation radiation so that radiation emitted from activated and excited PTOLs in the sample is emitted substantially from at least one volume that is comparable to or less than a diffraction-limited resolution volume (“DLRV”) of the imaging optics.