mRNA level-Pearson-Excel - (Jan/27/2009 )
I`m now analyzing correlation coefficient (Pearson) for mRNA level and fat content.
My problem is I`m not sure how to compute the mRNA levels (measured by Real-time PCR) in the Pearson formula and the scatter plot using Excel.
I was thinking to use the ∆Ct (target gene - reference gene), but then I found some papers using the 2-ΔΔCt, and one of them also used 2-ΔCt.
Also, I`ve been searching about how to make the scatter plot and trendline for this Pearson test in Excel.
Using Excel, I always end up with the graph for regression analysis and I don`t know how to make the graph or trendline into Pearson.
I checked the R values for regression and Pearson and they both are quite the same, although I`m kind of sure that the graph would be somehow different between those two tests.
Hope my questions aren`t (gramatically) confusing and anyone can help me because my head is spinning right now
The standard approach is to normalize your data, generally by using the control. Although I'm unfamiliar with the 2-dCt, I do understand how dCt is trying to normalize all data for mRNAs. Also, if your qPCR contains only relatively few samples, it may be good to try to calculate a p-value. As for the correlation coefficient, there is a simple function in excel (CORREL i think) which will calculate the Pearson coefficient for you.