Is it possible to remove the oily film and leave no traces on slides and coverslips in fluorescence microscopy?

Thus, there are different ways of effectively removing the grease layer from glass slides and coverslips during processes involving fluorescence microscopy.

Use of special cleaning agents: According to literature, determining appropriate solvents for physical or chemical cleaning is very important. There are organic solvents that can dissolve oils for example halogenated hydrocarbon solvents. However, one should note that these solvents may react with the surface of glasses and leave difficult-to-dissolve salts or metal ions. Hence, for such cases, they should be tested on a small scale to see what effect they have on the optical properties of slides and coverslips.

Ultrasonic cleaning: Ultrasonic cleaning is an efficient physical method for cleansing whereby mechanical vibrations created by sound waves assist in removal of grease as well as other types of contaminants which stick onto glass surfaces. This technique makes it possible to clean slides and cover slips irrespective of their size/shape without causing any harm.

Heat treatment: In literature Parafilm at high temperatures (60°C) has been found to have stable bonding properties as a dry mounting adhesive. It means therefore that heating can help in glass surface cleanup probably by making grease molecules soften due to high temperatures thus making them easier to get rid off.

Removal by rubbing: Though rubbing has been often mentioned in connection with contact lenses in literature, same principles could be used when purifying slides and slipcovers. Thus gentle rubbing may take away some lipids which bound itself upon the surface although this might require several runs before desired cleanliness is achieved.

Use of commercial cleaners: There are a lot of optical components cleaners available in stores having specific ingredients aimed at dissolving oil stains including other organic impurities. Before you choose any cleaner ensure that its contents will not harm slide’s or cover slip’s optical properties.

In summary effective removal of the grease layer on slides and cover slips with no residue is achieved by combining appropriate cleaning agents, physical cleanings and pretreatments.

References.

1.Ngai Keung Tam, W. Pitt et al. “Prevention and Removal of Lipid Deposits by Lens Care Solutions and Rubbing.” Optometry and Vision Science (2014). 1430–1439.

2.D. Whitlon and P. Baas. “Improved methods for using glass coverslips in cell culture and electron microscopy..” Journal of Histochemistry and Cytochemistry (1992). 875 – 877.

3.S. Filin, V. Rogalin et al. “Physical and chemical cleaning of the surface of power metal optics for the purpose of increase in beam firmness.” IOP Conference Series: Materials Science and Engineering (2020).