PCR duplicate rates are directly correlated to the quality and amount of starting material provided. Library preparation with less than the recommended amount of DNA requires additional PCR cycles to generate enough material to load the sequencer. Hence the PCR duplicate rate is dependent on the sample and cannot be influenced by Eurofins Genomics.
Duplicates are not excluded from the calculation of the average on-target coverage. Based on our experience with the sequencing of human samples, we typically obtain PCR duplicate rates of approximately 5% for high-quality DNA.
If further bioinformatics are ordered (e.g., SNP identification), only one copy of the duplicate read pair is kept in the alignment. The rest are excluded from further analysis to prevent any bias.