Easy lens cleaning solution for laboratory microscopes.

The most widely used technique to clean the objectives of a microscope, especially the 100X objective, involves wiping out of immersion oil from the same and its surrounding mount by a piece of lens paper or a soft piece of clean cotton cloth followed by a cloth dampened with small amount of xylol. The oil immersion objective is then dried immediately and cleaned with lens paper. Objectives should not be soaked with xylol because it may soften the cement holding the lens in its mount. Alcohol or acetone should not be used either, even for wiping the lens as these may also dissolve the cement. In addition, the oil immersion objectives which are in regular use and always come in contact with sticky oil can not be cleaned properly by wiping with xylol soaked cloth every time. World Health Organisation (WHO) specified criteria for cleaning the optics require a special solution, consisting of 40% petroleum ether, 40% ethanol and 20% ether.