By Monica Wachman Updated Mar 24, 2022
Microscopes enable scientists and students to study the cellular structures of plant and animal organisms, the crystalline patterns of minerals, and the contents of a single drop of pond water. To mount specimens in a manageable and contamination‑free way, researchers use microscope slides and cover slips.
Microscope slides and cover slips secure specimens in a stable, protected environment, making them easier to view and analyze.
A microscope slide is a long, thin glass (or sometimes clear plastic) panel, typically measuring 3 in. × 1 in., upon which specimens are placed for microscopic examination. Because specimens can be fragile and microscopic, handling the slide instead of the sample allows precise positioning. Many slides feature shallow depressions to hold liquid, enabling wet mounts. In a wet mount, a stain or solution is added over the specimen to highlight structural details and improve contrast.
Cover slips are small glass squares that sit atop the specimen on the slide. They flatten the sample, reduce evaporation, and, if liquid is present, keep it in place. By covering the specimen, cover slips also protect it from airborne contaminants and dust. The uniform pressure applied by the cover slip ensures an even, clear view for the observer.
A properly prepared slide—comprising a slide, specimen, and cover slip—offers dual benefits. First, it provides the observer with better control and a clearer view. Second, it shields the microscope itself: the cover slip acts as a barrier between the specimen and the ocular lens, preventing accidental scratches or damage, while the slide helps keep the stage clean and free of debris.
