The following notice was found affixed to a door in the main biology building on the campus of MIT. It appears below unaltered.
We are still having problems with injection oil ending up on the objectives. This messes up the optics and it is really annoying to sit down at the scope and find that all you can see is the blurry outline of a worm. Its a pain for me to have to clean up the objective. If the oil gets inside the objective it is ruined and must be sent to Germany for a repair which can take 6 months and cost over $500. All you need to do to avoid this is to be careful with the oil. If you want to leave a needle that is covered with oil in place then put a coverslip beneath it to prevent oil dripping on the objective. THIS IS IMPORTANT.