# How to get log2 fold change of RNA-Seq data for time series experiment?

I know if there is one control and one treatment group it is pretty straight forward to interpret log 2 fold change. But, I have time course experiment. I have infected cells with viruses and I harvested cells at different time points: o hr, 6 hour, 12 hr and 24 hour. Here o hr is my non-infected control. What is the best way to show log 2 fold change for each gene in this type of time course experiment. I ultimate aim to find highly expressed genes at different time points.

If you just want the change with time then use time as a continuous variable. The log2FC will then be the change per hour (you can use the default Wald test to extract it).