Coverslip

A coverslip, also called a coverglass is usually made of thin pieces of borosilicate glass that are used to cover specimens viewed on a microscope slide. Coverslips can be glued to the slide to preserve the specimen, slow drying, and prevent contamination. The thickness of the coverslip is critical for high magnification using "dry” objectives (no immersion oil) for optimum results in photomicrography. Choosing the correct thickness of coverslip is one of the most important tasks in obtaining high resolution and sharp photomicrographs. Using an incorrect thickness coverslip can cause spherical aberrations which result in soft hazy images.