When precipitating DNA, in a dna extraction, I used sodium acetate 3M, in falf of my samples, and in the other half I used potassium acetate 5M, but both are precipitating in form of granules after incubating at -20° overnight?
Are you using commercial or home made solutions. If home made how much of each salt is dissolved in what volume of water please? Are the salts hydrated or anhydrous in the solid form?
- Are you adding 1/10 final volume and not more ?
- If more then in effect you will saturate your solution; Hence the granules
Hello Mariana, how are you?
Well, sodium acetate will increase DNA precipitation, and it will precipitate together with your DNA for sure. I recommend you wash the DNA pellet with Isopropanol after the precipitation with sodium acetate, centrifuge, and discharge the isopropanol. Then, wash again with ethanol 70%. Resuspend your DNA in TE buffer. I do not incubate my samples at -20°C overnight, this also increase salt preciptation.
Paul Rutland They were home made solutions. For sodium acetate 3M i added 24.61 g CH₃ COONa . 3 H₂O brought it to 100ml final
and for potassium acetate 5M I added 49.07g of CH₃COOK /60 ml distilled water; and brought it to 100ml final.
For both reactions the pH was adjusted with glacial acetic acid
Laurence Stuart Dawkins-Hall For the precipitation overnight, i added 2.5 volumes of absolute ethanol and 0.25 volumes of sodium acetate. And for the other protocol, I added 1/10 with 1/5 of EDTA
- Badges
- Science method