Hello,

I have some RT-PCR data and have calculated the DDCT for each gene as the delta from the average of my housekeeping genes and the delta from my control (as a delta from the control housekeeping genes).

e.g.

DDCT = ([Ctgene]-[CtgeneHk]) - ([Ctcontrol] - [CtcontrolHk])

I have then calculated 2^-(DDCT) which I believe gives me gene expression as a fold change from my control.

However, I believe a better way to represent this data is as a Log2 transformation, so that I can represent under expressed genes as negatives, etc.

Please can you tell me if I perform the log2 transformation on the DDCT values, or the 2^-(DDCT) values? My initial thought is to use the DDCT values, however I am unsure how to account for the inverse logarithm of RT-PCR reactions.

Please can you explain your answer where possible.

Thank you