Cell-free DNA (cfDNA) are degraded DNA fragments released into the bloodstream through a natural process of cell death. During pregnancy, the mother’s blood contains cfDNA from her own tissue and from the fetus (cell-free fetal DNA (cffDNA)) via the placenta.  Sequence analysis of cfDNA from a sample of maternal blood can therefore provide genetic information about the fetus and inform clinical decisions without the need for invasive techniques like amniocentesis. However, as only between 2 and 20% of the total cell-free DNA in maternal blood is fetal1,2 (the fetal fraction), its analysis requires ultra-sensitive sequencing methods capable of accurately detecting genetic variants in samples with even the lowest of fetal fractions.

Targeted sequencing, through the use of custom designed NGS panels, offers a cost-effective method for the ultra-sensitive sequencing required for non-invasive prenatal genetics. Without the data burden of whole-genome sequencing (WGS) or whole-exome sequencing (WES) it allows researchers to achieve very high depths of coverage providing the increased sensitivity and accuracy needed for the analysis of low abundance cell free fetal DNA (cffDNA).

Cell3™ Target is a novel target enrichment system developed by Nonacus for converting cell-free DNA or genomic DNA into libraries for next generation sequencing that has been validated to ensure confident detection and analysis for even the lowest of fetal fractions.

We understand that our customers have different questions to answer so Cell3™ Target has been developed for and validated on cffDNA and gDNA for a range of prenatal applications. Whether you are using amniocentesis or non-invasive prenatal testing (NIPT), you know you will be able to use the same method and panel design.

Cell3™ Target enrichments incorporate error suppression technology including unique molecular indexes (UMIs) and unique dual indexes (UDI’s) which remove of both PCR and sequencing errors and index hopping events. This error suppression technique, combined with our excellent uniformity of coverage, allows you to confidently and accurately call variants in even the lowest of fetal fractions. (and from as little as 1ng cfDNA or gDNA input). We provide advice and provision of ready to go analysis scripts for error removal using UMI’s.

Figure 1. Using UMI’s to identify and quantify individual DNA molecules during library preparation increases sensitivity

Good design is key to a successful NGS panel ensuring adequate coverage and robust variant calling.  It’s not always easy to achieve, especially first time, but our Probe Design tool, makes it simple and easy allowing you to optimise panels in minutes. Create designs instantly from scratch using uploaded BED files, gene lists or genomic coordinates, customise catalogue products or add your own content onto one of our fixed panels.

• Easily merge, compare and share panels

• Get coverage data instantly and request a quote

• Receive your fully validated* custom panel within 4 weeks of order.

Log into the Probe Design Tool at My Nonacus  to start on a design and get a quote.

*All panels are NGS validated to ensure uniformity of coverage meets our QC requirements across all targeted regions

The baits used in Cell3™ Target are designed to deliver excellent uniformity of coverage. By improving uniformity of coverage and reducing the number of low coverage exons, our Cell3™ Target enrichment optimises sequencing efficiency and sample capacity per sequencing run ultimately reducing your sequencing costs.