PO.MCB08.03 · 分子与细胞生物学
将cfDNA优化的文库制备流程扩展至机械剪切的FFPE DNA,以获得高质量NGS数据
Extending a cfDNA-optimized library preparation workflow to mechanically sheared FFPE DNA for high-quality NGS data
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
福尔马林固定石蜡包埋(FFPE)组织是回顾性肿瘤学研究的基础,但由于DNA片段化、交联、碱基损伤和产量高度可变,FFPE样本对于二代测序(NGS)仍具挑战性。这些因素会影响文库转化和复杂度,并可能引入人为变异,从而干扰低频突变的检测。为应对液体活检中的类似挑战,Twist cfDNA文库制备试剂盒经过设计,能够从低输入量的游离DNA中生成高转化率、高复杂度的文库,其利用了优化的末端修复/连接化学以及Twist工程化的T4 DNA连接酶。我们证明该化学非常适用于经机械片段化的FFPE DNA。在此,我们评估了Twist cfDNA文库制备试剂盒在机械剪切的FFPE对照标准品以及从实体瘤蜡块中提取的FFPE DNA上的性能。
FFPE样本经处理和提取后,进行声波机械剪切。使用Twist cfDNA文库制备试剂盒和Twist UMI接头系统制备文库,随后使用肿瘤学聚焦捕获panel进行靶向富集,之后在Illumina仪器上测序。在不同DIN评分的FFPE样本中,cfDNA优化的流程在低输入量下生成了稳健的文库,具有高接头连接效率、改善的文库复杂度和均匀的靶标覆盖度。尽管FFPE质量存在差异,重复率和脱靶读长仍保持较低。基于UMI的共识调用有效抑制了FFPE相关的假象,实现了对与对照预期一致的低变异等位基因频率(VAF)体细胞突变的可信检测。随着输入质量的减少,性能趋势表现良好,支持对有限的档案材料进行测序应用。
这些结果表明,一种为低输入量、片段化cfDNA优化的文库制备化学可有效地重新用于机械剪切的FFPE DNA。将标准化机械剪切与Twist cfDNA文库制备试剂盒和靶向富集相结合,为液体活检和基于组织的NGS提供了统一的流程,扩展了Twist文库制备和靶向富集解决方案在具有挑战性的肿瘤学样本中进行敏感变异检测的实用性。
查看英文原文 English abstract
Formalin-fixed, paraffin-embedded (FFPE) tissues are a foundation of retrospective oncology studies but FFPE samples remain challenging for next-generation sequencing (NGS) due to DNA fragmentation, cross-linking, base damage, and highly variable yield. These factors impact library conversion and complexity and can introduce artifactual variants that confound low-frequency mutation detection. To address similar challenges in liquid biopsy, the Twist cfDNA Library Preparation Kit was engineered to deliver high conversion, high-complexity libraries from low-input cell-free DNA, leveraging an optimized end-repair/ligation chemistry with a Twist-engineered T4 DNA ligase. We demonstrate that this chemistry is well-suited for FFPE DNA that has been mechanically fragmented. Here, we evaluated the performance of the Twist cfDNA Library Preparation Kit on mechanically sheared FFPE control standards as well as FFPE DNA extracted from solid tumor blocks.
FFPE samples were processed and extracted, followed by acoustic mechanical shearing. Libraries were prepared with the Twist cfDNA Library Preparation Kit and Twist UMI adapter system followed by target enrichment with oncology-focused capture panels, before sequencing on Illumina instruments. Across FFPE samples of various DIN scores, the cfDNA-optimized workflow produced robust libraries at low input, with high adapter-ligation efficiency, improved library complexity, and uniform target coverage. Duplication rates and off-target reads remained low despite variation in FFPE quality. UMI-based consensus calling efficiently suppressed FFPE-associated artifacts, enabling confident detection of low variant allele frequency (VAF) somatic mutations that align with control expectations. Performance trends scaled favorably with decreasing input mass, supporting sequencing applications for limited, archival material.
These results demonstrate that a library preparation chemistry optimized for low-input, fragmented cfDNA can be effectively repurposed for mechanically sheared FFPE DNA. Combining standardized mechanical shearing with the Twist cfDNA Library Preparation Kit and target enrichment provides a unified workflow for liquid biopsy and tissue-based NGS, expanding the utility of Twist's library preparation and target enrichment solutions for sensitive variant detection in challenging oncology samples.
利益披露 Disclosure
S. Tighe, None..
O. Smith, None..
T. Truong, None..
T. Liu, None..
E. Lee, None..
E. Toro, None..
S. Chen, None.