During the RNA-Seq – Ultra Low library preparation process, primers and adapter sequences are added to the RNA during cDNA synthesis and amplification. These sequences are necessary for the sequencing process, but they are not part of the actual biological transcript. If left in the data, they can introduce noise and reduce the quality of the sequencing results. To ensure high-quality data, Eurofins will trim these sequences prior to delivery, which may result in slightly shortened sequencing reads.