0
$\begingroup$

If I have bacteria diluted in water and I centrifuge at max speed for 15-30 min, it is possible that I break the walls so the DNA can scape and I do not get any DNA pellet? or should I get it as a pellet everything togheter (lipids, proteins..) even if the mixure is just bacteria diluted in water?

$\endgroup$
  • $\begingroup$ At which relative centrifugation force (the "g number") do you work? And: Do you use plain water or do you add anything else? Where do these bacteria come from? $\endgroup$ – Chris Jan 16 '17 at 6:08
  • $\begingroup$ I recommend using a proper extraction kit. It may be possible (I mean anything can damage a cell wall) but you may not obtain a high yield. $\endgroup$ – Adam Radek Martinez Jan 19 '17 at 17:38
1
$\begingroup$

Not with bench centrifuges. Bacteria have cell wall and are rather small. This gives the cell wall alot of strength. I am not even sure that ultra centrifuges would work.

What you will likely get is a cell pellet. If you want DNA, pellet the cell and either go for direct PCR or sequencing. Or use a DNA extraction kit to obtain the DNA you want.

$\endgroup$
  • $\begingroup$ yes I use an ultra centrifuge. I am try to up-concentrate the sample but I cannot see any pellet and even when I remove volume and I resuspend the nonvisible pellet, I do real time pcr and it shows the sample was not up-concentrate, any idea why could that happen? $\endgroup$ – Bio Jan 15 '17 at 22:58
  • 2
    $\begingroup$ Why aren't you just lysing the cells first? Centrifugation isn't sufficient to lyse bacterial culture to a great degree. $\endgroup$ – Joe Healey Jan 15 '17 at 23:30
  • $\begingroup$ Because I use bacteria direclty to do real time PCR. $\endgroup$ – Bio Jan 16 '17 at 8:47
  • 1
    $\begingroup$ Why? You will get more accurate qPCR results with pure DNA anyway. People only normally do colony PCR from whole cells directly as it's a quick and dirty method for checking for transformants and so on. I've never heard of anyone doing qPCR from culture, and I can't really think why you would want to? $\endgroup$ – Joe Healey Jan 16 '17 at 14:18
  • $\begingroup$ because we use samples directly from a collector but maybe we could try to extract as you say. Thanks! $\endgroup$ – Bio Jan 19 '17 at 9:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.