Ultra-High NA Structured Illumination Microscopy

We measure the three-dimensional point-spread function and compare the resolution of three high numerical aperture objectives (NA) in a structured illumination fluorescence microscope using three-dimensional images of single quantum dots. Compared with conventional 1.30 and 1.42 NA objectives, the ultra-high 1.65 NA TIRF objectives offer significantly improved lateral spatial resolution of better than 75 nm using 488 nm excitation.