Vacuum pumps, gas cylinders, big containers of chemical waste... all things that be can heavy and that you don't want to drop for various reasons.
Oh, and we don't have a laser thingy anymore. MALDI is so last decade, it's all electrospray these days.
Edited, Dec 6th 2013 9:04am by someproteinguy
That monster in the mirror, he just might be you. -Grover