I am running experiments on cells which are given two different treatments. Treatment one is a control virus, and treatment two is an active virus. Due to the variability between cell lines, I always have to normalize the result from treatment two to that of the control treatment one. I then use a t-test to determine the significance between the treatment two (normalized) results and 1 (normalized control).
Now I am running the same experiments under a different condition (I'll call the first set condition A and this set condition B). Is there a test I can use to compare the normalized treatment two in condition A to the normalized treatment two in condition B? Or is it invalid to compare between the conditions because the data has already been normalized within that condition?
Thank you very much for any advice!