A cover slip is placed over the tissue on a microscope slide to protect the specimen, keep it flat, prevent it from drying out, and reduce the risk of the objective lens touching the sample, ensuring clearer viewing under the microscope.

You focus on low power first on a microscope to easily locate the specimen, get a wider field of view, and prevent damage to the slide or objective lens, making it easier to center and adjust the image before switching to higher magnification.