Immersion oil increases the resolving power of the microscope by replacing the air gap between the immersion objective lens and cover glass with a high refractive index medium and reducing light refraction.
Nikon manufactures four types of Immersion Oil for microscopy. These oils have been developed and tested specifically for use with Nikon objectives and therefore their performance cannot be guaranteed for lenses manufactured by other companies. Conversely, if non-Nikon oils are to be used with Nikon lenses, care must be taken to ensure that the refractive index and dispersion value of the oil match the properties of Nikon optics. Mis-match will result in aberrations and impair objective performance. It is also important to note that oils should not be mixed, as this will also impair performance.
Type N is a general purpose oil recommended for transmitted light applications, including brightfield, darkfield, DIC and phase contrast. It is available in 8ml (squeeze bottle), 50ml (squeeze bottle) and 480ml (bottle with pipette) quantities.
Type B is compatible with Nikon's Perfect Focus System (PFS) and is recommended for transmitted light-based time-lapse imaging experiments. Type B is available as a 30ml bottle (glass rod is included for dispensing).
Type F is designed to ensure the highest image quality for fluorescence applications, with maximal signal-to-noise ratio and minimal autofluorescence. Type F is also compatible with Nikon’s Perfect Focus System (PFS), enabling drift-free, long, time-lapse imaging experiments and is available as a 30ml bottle (glass rod is included for dispensing).
Silicone immersion oil is used for deep observations of live specimens.
Silicone oil (ne≒1.40) closely matches the refractive index of cells (ne≒1.38) thereby minimizing spherical aberration when imaging through thick biological samples, resulting in bright, high-resolution images. Unlike water, silicone oil exhibits virtually no evaporation even at 37˚C, enabling extended, long time-lapse experiments without the need to replenish immersion medium. Silicone oil is available as a 30ml bottle (glass rod is included for dispensing).