If your microscope has a cover or case, always put it in place when you arent using the device. Wet or dirty slides should never be put on the stage, which should always be kept dry. When cleaning your microscope, unplug it first, if applicable, and then clean the outside using a damp, soft cloth only. Never use a dry cloth or paper towel to wipe any optical surface as you could scratch a lens. Use an air blower or a camel hair brush to whisk away dust. If there is dirt on the eyepiece that cant be removed with air or the brush, gently wipe it with a piece of clean cotton. If you must clean the objective lens, use xylitol or absolute alcohol. Never try to clean or take apart the internal pieces of the microscope.