Nikon's newly developed high N.A.objective provides a cone of illumination that facilitates incident laser illumination beyond the critical angle().This results in total internal reflection, and creates an evanescent wave immediately adjacent to the coverglass-specimen interface. Total internal reflection fluorescence (TIRF) microscopy takes advantage of the evanescent wave to excite fluorescent molecules only in the thin section in contact with the coverglass.The lack of fluorophor excitation beyond the evanescent wave results in an extremely high signal-to-noise(S/B) ratio.

The unique extendible configuration of Nikon's TE2000 inverted microscope permits simultaneous mounting of both TIRF and epi-fluorescence illumination systems, with no restriction of their individual capabillties.This configuration facilitates easy switching between TIRF and epi-fluorescence, or simultaneous imaging.