[BioC] how to design comparision using edgeR

[wang peter]

dear jim
 thank you very much for your help, my question is
yes, i want to find  treatment vs control comparison, adjusted for time.
but only between 6h vs 0h

not all the time
if glmLRT(dge, glmfit.dge)
it means DE happened due to treatment at any time point

thx

should i use only samples on 6h and 0h,removing other samples to do glmFit
and
glmLRT(dge, glmfit.dge)