Water Dipping Objectives | Water Dipping Objectives

Key Words: Live cell imaging, N.A., oil immersion, resolution, spherical aberration, water immersion, deep cell imaging

Definition:Microscope objectives designed for observing tissue directly (no cover glass) i.e. where the lens is dipped directly into the medium of tissue culture dishes containing tissues or cells

TECHNOLOGY:

Water dipping lenses are designed to work without a cover glass and can be dipped directly in the cell culture dish. Typically, the N.A. is slightly lower than water immersion lenses (e.g. Plan Fluor 100x, N.A 1.1 compared to Plan Fluor 100x, N.A. 1.3) but the working distance is much longer -“ up to 2.5 mm. The combination of water dipping and long working distance enables micromanipulation at extremely high magnifications. Because the N.A. of water dipping lenses is still relatively high, they can also be combined with digital imaging or laser scanning confocal microscopy.

APPLICATIONS:

Water dipping objectives are ideal for deep tissue /live cell imaging. Long working distances make the objectives ideal for any application requiring micromanipulation, such as physiology, imaging of brain tissue and IVF applications. Nikon's CFI60 water dipping objectives have been designed with high transmittance in the near infrared and ultraviolet for applications such as IR DIC and Ca2+ imaging with FURA-2.

MICROSCOPE CONFIGURATION:

Water dipping objectives provide the ideal accompaniment to Nikon's FN-1 physiology station where long working distances, a 60mm parfocal distance and narrow front assembly, allows easy access for manipulation equipment. Water dipping lenses, in addition, are isolated from thermal and electrical transmission to the specimen for optimum results in electrophysiology applications.

Nikon's water dipping FLUOR objectives include:

CFI Fluor 10xW, N.A. 0.3, W.D. 2.0 mm
CFI Fluor 20xW, N.A. 0.5, W.D. 2.0 mm
CFI Fluor 40xW N.A. 0.8, W.D. 2.0 mm
CFI Fluor 40xW DLL, N.A. 0.8, W.D. 2.0 mm
CFI Fluor 60xW N.A. 1.0, W.D. 2.0 mm
CFI Plan 100x W, N.A. 1.1, W.D. 2.5 mm

Nikon's water dipping APO objectives include:

5CFI75 LWD 16X 0.80 N.A. W.D. 3.0 mm
CFI60 10xW, NA 0.3, W.D. 3.
CFI60 40xW, N.A. 0.8, W.D. 3.0 IR
CFI60 60xW, N.A. 1.0, W.D. 3.5, IR
CFI60 100xW, N.A. 1.1, W.D. 2.5, IR/C

RECOMMENDED SYSTEM:

The Plan 100x W objective (N.A. 1.1, W.D. 2.5mm) has a correction collar designed to correct for spherical aberration induced by imaging deep in tissue or by working at physiological temperatures. The results are outstanding z-axis resolution for IR-DIC and multiphoton imaging applications. This objective in combination with the FN-1 electophysiology microscope provides the ideal system for deep tissue imaging.

The CFI75 LWD 16x 0.80 NA objective features a working distance of 3.0mm and a 45 degree manipulator approach angle. This 'Best of Breed' combination of numerical aperture, long working distance and approach angle provides a one-lens solution for electrophysiology applications. When used with the FN1's variable magnification double port (optional), this objective allows intermediate magnifications between 0.35x, 2x, and 4x. It is also possible to observe from a low magnification widefield to a high magnification, high-resolution field with the same 16x objective. This feature provides the flexibility to image large structures, such as the hippocampus, as well as small structures, such as axons and dendrites, with the same lens. The 0.35x intermediate magnification allows a 2.0mm field of view, enabling easy electrode handling under macro observation.

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