Protocol Online logo
Top : Forum Archives: : Molecular Cloning

DNA pellet won't go into solution - (Sep/10/2007 )

hi all,
I am isolating Bacmid for transfection into insect cells. My pellets won't go into solution (TE).
What should I do?=?
thanks

-pras45-

ok bacmid are tough. First gently wash pellets with 70% ethanol at not too igh speed to ensure good salt wash and partial hydratation. I mean 80% ethanol does not help to the resuspension step. Seem you've overdried your pellet as it encounters difficulties to resuspend. But : do you have a gel-like pellet ? it may be RNA.
So try at first heating 55° 10' and see if it dissolves. If you still see pellet, go for 65° 10', check OD and run an aliquot on agarose gel to see if you don't have RNA. In taht case redo RNase, poteinase K and phenol chlo.

-fred_33-

Thanks, but RNase should should take care of that right?The pellet doesn't have gel look, it is still like whitish flake. I read the OD and 260/280 was 1.91 and had 1.4 ug/ul DNA, which rules out protein contamination. I will run it on the gel. I tried heating @ 50 degree but wouldn't dissolve.
Normally, I incubate DNA pellet (Maxi, Midi) @ R.T until the pellet becomes transperant, but this time I did more than 10 mins (suggested by protocol) and did not see change in the appearance. So, I added TE and now the pellet wouldn't dissolve.

-pras45-

Leave it in the fridge overnight. Large DNA fragments can take hours to dissolve. If it's in TE then you could leave it at RT or 37C, but I wouldn't do that without some EDTA present.

-phage434-

Try adding warm TE 60C and leave it at 37C waterbath .

-scolix-