Microscope Cover Slip

Cover glass (cover slip, coverslip, microscopic glass) is a thin flat piece of transparent glass, usually square or rectangular, about 20 mm wide and a fraction of a millimetre thick, that is placed over objects for viewing with a microscope. The object is usually held between a cover glass and a glass slide, which rests on the microscope's stage or slide holder and provides the physical support for the object and slip.

The cover glass often has several other functions. It holds the specimen in place (either by the weight of the cover glass or, in the case of a wet mount, by surface tension) and protects the specimen from dust and accidental contact. It protects the microscope's objective lens from contacting the specimen and vice versa; in oil immersion microscopy or water immersion microscopy the cover glass prevents contact between the immersion liquid and the specimen. The cover glass can be glued to the slide so as to seal off the specimen, retarding dehydration and oxidation of the specimen. Microbial and cell cultures can be grown directly on the cover glass before it is placed on the slide, and specimens may be permanently mounted on the slip instead of on the slide. Cover glass is one of most commonly used laboratory glassware, laborat