Immersion Oil (15 ml) is required for using OIL-marked objectives on biological microscopes. As this objective is positioned just a hair's breadth above the slide, it can achieve its maximum resolving power through an oil with a refractive index similar to that of glass. The oil applied between the glass cover slip of the specimen and the glass surface of the objective eliminates the image-degrading effect of air with its different refractive index. After use, it must be removed from the slide using optical cleaning fluid.
The product is supplied in a 15 ml bottle with a dropper cap for easy application.
The refractive index of the immersion oil: 1.515–1.520 (at 20°C).