a piece of equipment that spins tubes really fast, pulling heavier molecules out of solutions and leaving you with a solid pellet and liquid (supernatant) on top. (or, as a verb, the process of using a centrifuge). The amount of separation you get depends on how fast you spin, and we have lots of types of centrifuges for different purposes. Centrifuges come in lots of different sizes, and within those different sizes, you can use different inserts to hold different size tubes, bottles, or even plates. We use the bigger ones for things like separating insect cells expressing our protein from the media we grow them in (we call this harvesting). We use the medium ones 4 things like concentrating proteins and pelleting small bacterial cultures. We also have microcentrifuges that we use with, you guessed it – microcentrifuge tubes!
Centrifuges can be “fixed angle” or “swinging bucket.” You can think of swinging bucket as kinda like swing rides at amusement parks where the seat can move & fixed rotor would be more like the teacups where the “seat” can’t move. Some of our centrifuges have coolers so we can control the temperature. This is important when working with temperature-sensitive things like proteins.
So far, I’ve shown you “regular” centrifuges, but we also have “ultracentrifuges” that go even faster. We use these during protein preparation to separate soluble proteins from “cell gunk.” We also have centrifuges that go slower. Why would you want that? Sometimes, you just need to draw liquid drops off the sides of small tubes -> just want something quick & gentle. Mini “pulse” centrifuges are great for this. They only have one set speed but you can let it spin as long as you need & quickly get your samples in & out (centrifuges that spin faster take longer to wind down)