What is the recommended cleaner for removing oil from microscope objectives?

The recommended option for removing oil from microscope objectives is 70% alcohol or lens cleaner because these substances effectively dissolve and lift oil residues without damaging the delicate coatings on the lenses. 70% alcohol is broadly used in laboratory settings due to its ability to evaporate quickly and its low toxicity compared to other solvents.

Lens cleaners are specifically formulated for optical surfaces, ensuring that they clean without scratching or leaving residues that could impair viewing. This makes them ideal for maintaining microscope optics in good condition.

In contrast, other options, like xylene and benzene, are harsher solvents that can potentially harm optical coatings and are not safe for regular cleaning of sensitive optical equipment. Water, while generally safe, is ineffective at breaking down oil, making it an inappropriate choice for this particular cleaning task.