Just wondering is there a maximum speed I can spin bacteria. I just need to make a pellet in the shortest time possible but I dont want to damage the cells. Is it damaging at say 100,000 rpm/ 1min?
We always use 10,000- 13,000 x g for 1-2 minutes in a microcentrifuge.
100,000 RPM might be a bit much.
Bacteria are heavy so they’ll pellet with less force.
I don’t know but I would guess that at 100,000 RPM, it would take about 10 seconds to pellet bacteria- it would take longer than that for the centrifuge to reach that speed.
I agree with Suzanne. To get to 100,000g/rpm, you would need to use a ultracentrifuge, and it takes a significant amount of time to get up and running and then slow down and stop. I would also be worried about damaging the cells at 100,000g/rpm.
If you are using the pellet after this step, you can pellet the cells in 20-30 seconds in a microfuge. You leave more cells in the supernatent than you would if you spun then for 1-2 minutes, but if you are more concerned with speed than you are with quantitative recovery of the cells, then this might work for you.
I don’t know how much force cells can handle, but I think the important question should be “How much force do I need?”
Even if cells can withstand 100k rpm, you probably don’t need that speed. For e.coli in LB, 20 seconds at 13k rpm in a microfuge will pellet the cells well.
Cheers folks, I dont know where I was getting 100,000 from I meant 10,000 rpm. They are helpful insights, appreciate it.
I agree with Suzanne. Usually centrifuging liquid cultures at 10,000 rpm from 3 – 5 min gives a very sturdy pellet and the supernatant can be discarded easily.
I’m still looking into this issue but since this question was asked an article was published suggesting that many people centrifuge their bacteria unnecessarily fast, stripping their coatings and reducing their viability (and virulence). It varies depending on the bacteria type and container shape but in any case, E. coli (all I ever use) are among the more sensitive ones.
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