statistical problems - (Sep/02/2008 )

Hi everybody.
I have a problem with handling error bars in my graphs.
The fact is I want to graph a fold increase in gene expression after treatment of my cells.
I use DCt method. I can calculate DCt, DDCt, St dev and SE. i know how to visualize error bars if i graph DDCt results, but what shall i do with my fold increase? the fold is calculated as 2exp(-DDCt), but what about my error bars? how do i calculate it?
Can anybody help me?
Thnx
Fizban

Start from stdev for DCt, to calculate the total Stdev for DDCt as calculating Stdeve for x1-x2 in t test (I think you are familiar to it). And then do calculation stdeve using 2exp(stdv) for 2exp(-DDct).