I have a problem with preparation of genomic DNA libraries.
DNA shearing was performed with Covaris to get a fragment lenght between 50 and 200 bp (checked on gel). After end repair and A tailng, ligation with adapters (around 120 bp total), DNA was amplified by PCR, purified and then checked again on gel. Most of the fragments were between 200 and 450 bp, so at least 50 bp higher than what I was expected. Did anyone experience something similar?
DNA shearing was performed with Covaris to get a fragment lenght between 50 and 200 bp (checked on gel). After end repair and A tailng, ligation with adapters (around 120 bp total), DNA was amplified by PCR, purified and then checked again on gel. Most of the fragments were between 200 and 450 bp, so at least 50 bp higher than what I was expected. Did anyone experience something similar?