I have about 20-30 grams of purified mammalian DNA preserved in EDTA. It is clumped up and solid. I need to dissolve and homogenize it, so it can be aliquoted, without damaging or lysing or fragmenting the DNA. What is the best way to do this?
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$\begingroup$ I think you can do this with TE buffer or water, the latter of which needs to be 18 M$\Omega$ RO. $\endgroup$– Todd MinehardtDec 1, 2021 at 17:13
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$\begingroup$ How large are the DNA pieces (eg number of base pairs)? That’s a big factor in how susceptible they are to mechanical damage. If it’s a small plasmid, you can pipette vigorously without much worry, but if it’s genomic DNA you need to be much gentler $\endgroup$– AndrewDec 2, 2021 at 1:51
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$\begingroup$ @Andrew I updated the questions. It's mammalian genomic DNA. $\endgroup$– Shaka BoomDec 2, 2021 at 12:41
1 Answer
I suspect you'll get a much better answer if you migrate this question to biology SE, but here's what I've done:
add your chosen volume of nuclease-free TE buffer or water (assuming the DNA is precipitated with salts).
Leave it in the fridge (~4 C) overnight to allow for slow hydration.
Gently resuspend the DNA by very slowly pipetting the solution up and down using a 1 mL pipette with about 1 cm of the tip cut off so that the opening is substantially larger than normal.
Make aliquots for future use so as to minimize handling.