What is the purpose of a cover slip in microscopy?

The purpose of a cover slip in microscopy is to protect the specimen and improve image quality. When a cover slip is placed over a specimen, it serves several important functions. Firstly, it acts as a physical barrier that helps to safeguard the specimen from damage, contamination, or potential interference from the environment. Secondly, the cover slip aids in creating a uniform thickness, which is critical for optimal focus and clarity under the microscope. This uniformity contributes to better light transmission and can enhance the overall image quality by reducing distortions that might arise from variations in the specimen's thickness.

In this context, while other options touch on aspects that might seem related to microscopy, they don't accurately capture the primary role of a cover slip. For instance, increasing visibility is more about the inherent characteristics of the specimen and the microscope's optics rather than just the cover slip. Similarly, while manipulating slides is influenced by their design, making it easier isn’t the intended function of the cover slip. Preventing specimen drying is important, but the cover slip primarily serves to protect the specimen and ensure that the image captured through the microscope is as clear and accurate as possible.