FAQ: Can libraries be prepared from FFPE DNA using the NEBNext® EM-seq Kit (NEB #E7120)?
Note that libraries prepared from FFPE DNA may have higher methylation backgrounds in the CHH and CHG contexts. However, use of a 3xC filter (available in the Bismark pipeline) or similar, reduces background. The filter removes reads that contain 3 or more consecutive unconverted Cs in the non-CpG context (i.e., CHG/CHH).