A biological microscope is a type of optical microscope designed for observing cells, tissues and other biological samples.  Various objective lenses can be fitted to the microscope, providing magnification ranging from 10x to 1,000x and above. As these systems are mainly used to examine specimens placed on flat surfaces (for example, on microscope slides, in Petri dishes, on slides, etc.), the objectives have short working distances and high numerical apertures. Some specialised versions of these microscopes are capable of fluorescence imaging and are better known as fluorescence microscopes. Unlike conventional microscopes, biological light microscopes are specifically designed to provide optimal conditions for viewing biological samples.