The mounting medium can have a strong impact on how the specimen appears under the microscope. If you want to observe a specimen under the microscope, then you have to add a mounting medium. The mounting medium is important for several reasons:

• Stability: It mechanically stabilizes and supports the specimen. Delicate structures can not break off.
• Preservation: It prevents moisture and bacteria from reaching the specimen, which might decompose it.
• Improves image quality: The refractive index (RI) of the mounting medium can have a significant impact on the image quality.