With a numerical aperture of 1.7, the NA 1.7 APON100×HOTIRF objective achieves a high Z-resolution for a total internal reflection fluorescence (TIRF) microscope. The lens can improve single-molecule dynamic studies due to the enhanced signal-to-noise ratio offered when detecting surface-bound molecules, with reduced background emission from molecules in the surrounding solution. The new objective is also designed to provide the performance required for super-resolution applications and TIRF co-localization studies. With a magnification of 100x, the new TIRF objective is also suited for in vitro TIRF microscopy.