Help! DNA insoluble in water

Nanfel Xu nxu at
Mon Oct 17 13:42:09 EST 1994

Dear netter:
	It drives me crazy that my DNA won't dissolve in water!  I put 60 
ug plasmid DNA (pUC19 + 1.5 kb insert) in 60 ul water and digested it 
with Nco I, phenol extracted, precipitated with 2 vol. ethanol, washed 
and dried in a Speed-Vac (5 Min.), and I cannot get it dissolved in water 
again.  I also tried phenol/chloroform extraction and no extraction, 
drying at 65C or at room temperature.  Nothing has worked repreducibly.  
What I did wrong?  What can I do to make this DNA dissolve in water?

P.S.  I tried precipitating the same DNA without digestion.  It dissolved 
in water perfectly no matter how it was dried or precipitated.

Nanfei Xu

More information about the Methods mailing list