For QuantSeq REV, it is essential to use the Custom Sequencing Primer (CSP Version 5; (provided with the QuantSeq kit) for Read 1 sequencing.
Make sure that your sequencing facility is aware of this. When handing in QuantSeq REV libraries for sequencing, please include these guidelines for CSP useage: What is the CSP and the information on how to use the CSP. The CSP should never be mixed together with the standard Illumina Read 1 Sequencing primer. A primer mixture would result in low clusters calls and the resulting reads would be contaminated by poly(T) stretches. do I use it?