Water Immersion Objective

In light microscopy, a water immersion objective is a specially designed objective lens used to increase the resolution of the microscope. This is achieved by immersing both the lens and the specimen in water which has a higher refractive index than air, thereby increasing the numerical aperture of the objective lens.Water immersion objectives are used not only at very large magnifications that require high resolving power, but also of moderate power as there are water immersion objectives as low as 4X. Objectives with high power magnification have short focal lengths, facilitating the use of water. The water is applied to the specimen (conventional microscope), and the stage is raised, immersing the objective in water. Sometimes with water dipping objectives, the objective is directly immersed in the solution of water which contains the specimens to look at. Electrophoretic preparations used for instance in the cases of Comet Essay can benefit largely with water objectives.