Replicate in the design formula

Question

[indrik.wijaya]

Hi, I am doing differential expression analysis on RNA-seq data and have been wondering when we should include 'replicate' into our design formula. I found both cases where 'replicate' is included and not included. Thank you for the help.

[manuel.belmadani]

Technical or biological replicates?

[indrik.wijaya]

Hi, it's biological replicates