New Developments in Sample Quality Control – Focus on Cell-free DNA

Abstract
Quality control of nucleic acid starting material is essential to ensure the success of downstream experiments. Especially, Next Generation Sequencing (NGS) developed to a powerful tool in almost all genetic research and diagnostic areas. Due to the establishment of low input library protocols for NGS workflows sequencing of cell-free DNA (cfDNA) became possible. Since the downstream applications are often time-consuming and expensive, tight QC steps are required to avoid a “garbage in-garbage out” situation. This talk focuses on standardized nucleic acid quality assessment using different automated electrophoresis platforms to ensure that samples are “fit for purpose”. Accurate quantification of starting material (DNA, RNA, cfDNA, FFPE samples) is essential to determine suitable input amounts for library preparation prior to sequencing. Depending on preanalytical sample treatment or extraction methods the quality of e.g. cfDNA can vary. This results in various electropherogram patterns after electrophoretic separation as presented in this talk. Moreover, the electrophoretic separation enables to qualify cfDNA samples according to their contamination level with high molecular weight material. Likewise, quality scores for gDNA, RNA as well as FFPE RNA can be assessed using automated electrophoresis systems, which allow defining a quality threshold for specific types of samples or preparation. This allows defining thresholds for objective sample qualification prior to library preparation.