# DeltaDelta Ct method and Statistics - (Jan/28/2010 )

Hey,

I performed RT-PCR on my samples which are grouped into 6 different treatment groups. I used the deltadeltaCt method to end up with a mean fold change in mRNA levels.

So I have a Delta-DeltaCt value for each of 6 different treatment groups but not for my individual samples.

I then calculate the mean fold change so I end up with a number for each of my groups compared to the non-treated group.

But now, I do not know how to compare these data. I make a graph and i see a clear difference between some groups but I do not know which test to use because I only have one value for each column and my stat-program (GraphPad) says it does not have enough data to calculate p-values.

Can anyone help me, please??

Thanks

If you perform 3 PCR runs then you will have 3 replicates in which to compare.

hope this helps,

AussieUSA.

Blackeyed on Jan 28 2010, 01:33 PM said:

I performed RT-PCR on my samples which are grouped into 6 different treatment groups. I used the deltadeltaCt method to end up with a mean fold change in mRNA levels.

So I have a Delta-DeltaCt value for each of 6 different treatment groups but not for my individual samples.

I then calculate the mean fold change so I end up with a number for each of my groups compared to the non-treated group.

But now, I do not know how to compare these data. I make a graph and i see a clear difference between some groups but I do not know which test to use because I only have one value for each column and my stat-program (GraphPad) says it does not have enough data to calculate p-values.

Can anyone help me, please??

Thanks

You could try to use the free software pyqpcr that calculate relative quantifications and proper error (you can choose the confidence level, and the way it is calculated : Gaussian or T-test). In this software the error is propagated from the error on your triplicates and if pertinent from the PCR efficiency of your primers. You should obtain your result easily. I hope this is useful.