cDNA concentration higher than original RNA - (Jan/19/2010 )

Hi,

my RNA has 1.8 ng/ul concentration but the cDNA that I made from it has 1.2 ug/ul concentration. Even higher.

How is this possible when I used only 2 ul of RNA as tamplate in 20 ul reaction. I mean the cDNA concentration must be even lower, but now it is higher. How?

Did you take into consideration when doing the calculation that cDNA is both double stranded and a heteroduplex?

I do know that, but during measurement with Nanodrop we consider cDNA as ssDNA. This is what the company told us. But still doesn't matter if we consider it as double strand or single strand, the cDNA conc. is still higher. is it always like that?

try putting some dNTPs through the spec/nanodrop...

After purifying your cDNA, the resulting concentration would be much lower.