Excuse me:

The SureSelect protocol said that we should add 'A' bases to the 3' end of the DNA fragments. Could someone tell me the purpose of this procedure?

Many thanks in advance!
<p>As far as I know, this is not specific to SureSelect, it&#39;s all Illumina ligation-based protocols.</p>

<p>When you ligate the sequencing adapters to the target insert, it helps get adapter to insert ligation, because the adapters have a T overhang on their 3&#39; ends and can pair. The inserts or adapters ligate to themselves much less efficiently because they will have A-A or T-T mismatches.</p>
