After using Combat-Seq to remove batch effect, I want to visually confirm removal. I tried doing this the way I visually inspected the batch effect in the first place: PCA on VST-transformed counts. But VST-transform cannot be used on negative values (which Combat-Seq has introduced). How can I confirm that the batch effect has been removed then?
I tried PCA on the batch-corrected counts without any further transformations, but there are no clear patterns.
Are you sure you didn't use
ComBat
instead ofCombat_seq
?