Twist cfDNA Pan-cancer
Reference Standards

Comprehensive Cancer Variant Reference Standard for Liquid Biopsy Research

NGS-based liquid biopsy is a rapidly evolving application that requires accurate and precise reference standards. The Twist Pan-cancer Reference Standard is a high-quality, standardized control for use in the research and development of NGS-based liquid biopsy assays. This reference standard is ideal for establishing the analytical limit of detection (LoD) for specific cancer variants and as a control to track the quality of an NGS assay workflow and assess the fidelity of the assay process during research and development of such assays.

Traditional reference standards are limited in the number and variation of variants and typically use cell line-derived DNA which can carry unwanted sequence variations and variable fragment length. The Twist cfDNA Pan-cancer Reference Standard incorporates a large and diverse set of variants for research use. This reference standard utilizes accurate DNA synthesis of variants with precise control over the specific variant allele frequencies (VAF) to produce a reference standard which closely mimics the size distribution and fragmentation profile of cell-free and circulating tumor DNA enabling higher performance assay development.

This reference standard consists of synthetically designed variant sequences that mimic circulating tumor DNA (ctDNA), combined with background DNA that is derived from, and closely mimics, human-derived cell-free DNA (cfDNA). The ctDNA sequences are designed as a tiled pool of ~167 bp sequences that closely mimic natural ctDNA and cover 458 individual mutations with 132 clinically actionable variants across 84 genes associated with cancer.