Since the microscope uses visible light and visible light has a set range of wavelengths. The microscope can't produce the image of an object that is smaller than the length of the light wave. Any object that's less than half the wavelength of the microscope's illumination source is not visible under that microscope.

When you use a microscope you should never?

IMPORTANT: Never use coarse focus except with the low power objective lens! It is very easy to drive an objective through a slide. This destroys the slide and can scratch the lens! The ratchet mechanism for moving the stage is thrown out of alignment when only one knob is turned during focusing.

Why is microscope not working?

Check to see if your microscope is plugged in. Check to see if the bulbs are installed correctly. ... If the bulbs are installed, check to make sure they are not loose, which sometimes happens during shipment. Check the rheostat (light intensity control) on the side of the microscope.