Guys, based on my OD260 I'm getting nanograms/ul of dsDNA. When I ran the same amount on a gel, I got >2 micrograms/ul. Can you explain that? Ricky >>, are you using the OD conversion for double stranded DNA at 50ug/ml >>= 1 OD or the single stranded of 33ug/ml = 1OD? >