<P> In light microscopy, oil immersion is a technique used to increase the resolving power of a microscope . This is achieved by immersing both the objective lens and the specimen in a transparent oil of high refractive index, thereby increasing the numerical aperture of the objective lens . </P> <P> Immersion oils are transparent oils that have specific optical and viscosity characteristics necessary for use in microscopy . Typical oils used have an index of refraction around 1.515 . An oil immersion objective is an objective lens specially designed to be used in this way . Many condensers also give optimal resolution when the condenser lens is immersed in oil . </P>

What is the use of immersion oil in microscopy