Hi

I have two replicates for two conditions ( resistant and sensitive ) at two time intervals for conducting a Differential Expression analysis using edgeR. How do I assign the condition for ' group ' in DGElist function? My data would look like R1,R2 vs. S1,S2 at one time interval and R3,R4 vs. S3,S4 at another time interval. Kindly guide.

Read Chapter 3 of the edgeR user's guide, in particular Section 3.3.