Olympus UAPO N 100X TIRF Objective 1.49 NA Oil Immersion

The Olympus UAPO N 100× OTIRF objective is engineered for total internal reflection fluorescence (TIRF) microscopy and advanced high-resolution fluorescence imaging. With an ultra-high numerical aperture of 1.49, this objective enables precise excitation at the glass–sample interface, making it ideal for single-molecule imaging, membrane dynamics, and surface-localized fluorescence studies. The apochromat optical design delivers exceptional chromatic correction, contrast, and signal efficiency across the visible spectrum—essential for demanding live-cell and multi-color fluorescence applications.

TIRF microscopy requires ultra-high NA objectives (≥1.45) to generate the critical angle necessary for total internal reflection. The evanescent field produced penetrates only ~100–200 nm beyond the coverslip surface, selectively exciting fluorophores at the cell membrane while eliminating background from the bulk of the sample. The 1.49 NA of this objective maximizes the usable angle range for TIRF, delivering exceptional contrast and signal-to-noise ratio for single-molecule detection and membrane imaging. Lower NA objectives cannot generate a proper evanescent field and result in poor signal and high background.

The correction collar compensates for optical path variations to maintain optimal image quality across different coverslip thicknesses and mounting conditions. The infinity-corrected optical design is compatible with Olympus BX, CX, and IX series microscopes, with a 180 mm tube lens and field number of 22 mm.

TIRF vs Standard Fluorescence Objectives

TIRF Objectives (e.g., this objective, NA 1.49)

Ultra-high NA (1.45–1.70+)
Excite only a thin surface layer (~100–200 nm)
Extremely high contrast and low background
Best for:
・Membrane imaging
・Single-molecule detection
・Live-cell surface dynamics
・Standard Fluorescence Objectives

Lower NA (0.75–1.40)
Illuminate entire sample depth
More background fluorescence
Better for:
・General fluorescence imaging
・Thick samples and tissue sections