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effect of dna with ethanol overnight - (Aug/08/2005 )

hi, just want to ask if ever there will be any effect on the quality of dna if i dry my dna pellet with ethanol overnight?
I use promega wizard genomic dna kit and it specifies that dry the pellet for 15 minutes after ethanol washing and precipitation, then add rehydrating solution of tris-hcl. I dont follow the 15 minutes since there are still ethanol in my dna that is why i leave it overnight. Will it affect my dna sampe for pcr if it is too dehydrated?
thanks

-phoenix77-

If the DNA pellet is dried too much it wont dissolve in H2O or TE easily. Use vacuum drier, or keeping inverted at RT for ~20 min is enough. (I generally keep it in straight position on dry Heating block set at ~ 37C for 5-8 min)

-Molonco-

If your DNA dries too much not only will it be more difficult to resuspend, as stated by Molonco, but it will incur random double-stranded breaks, which may affect the quality of your PCR.

-mantispid-

QUOTE (phoenix77 @ Aug 8 2005, 08:26 AM)
hi, just want to ask if ever there will be any effect on the quality of dna if i dry my dna pellet with ethanol overnight?
I use promega wizard genomic dna kit and it specifies that dry the pellet for 15 minutes after ethanol washing and precipitation, then add rehydrating solution of tris-hcl. I dont follow the 15 minutes since there are still ethanol in my dna that is why i leave it overnight. Will it affect my dna sampe for pcr if it is too dehydrated?
thanks


After 15 minutes all ethanol is gone, you might have some water. If your DNA dry too much it will be harder to eluteand harder to work with.

-IMi-

If your DNA doesn't dry after 15 minutes at room temp then you didn't remove enough of the ethanol. Remember that any salt in the sample will not evaporate away so if you are leaving too much ethanol then you will end up with salt in your sample.

Daniel

DNA sequencing programs

-Daniel Tillett-

actually, i dry my pellet over night quite often - before sequencing it...and i have had no problems with that at all!

-janbrisbane-