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Precision indexing for cell-free DNA (cfDNA) methylation analysis

Maximize epigenetic study resolution with adapters built for low-diversity cfDNA methylation libraries. Fully compatible with the Twist Methylation Detection System and target enrichment workflows, this system enables accurate deduplication by preserving fragment integrity and library complexity for reliable liquid biopsy research.

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Improve library complexity

Preserve fragment length and diversity to ensure high-resolution mapping of methylated sites across the entire genome.

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Increase sequencing efficiency

Minimize false duplicate calls with UMIs, allowing for more productive sequencing runs.

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Improve data reproducibility

Achieve higher mean target coverage and consistent performance across samples for more reliable epigenetic biomarker discovery.

Product data

UMI informed duplicate calling reduces library duplicates by over 15%, leading to an increase in library complexity (25–35%) and mean target coverage (6–8%) compared to standard positional based duplicate calling.

EM-seq libraries were generated from 10 ng of human cfDNA using either NEB EM-Seq adapters or Twist Methylated UMI Adapters. Libraries were captured with the Twist Alliance Pan-Cancer Methylation Panel (1.5 Mb) using the Targeted Methylation Sequencing Protocol and sequenced on an Illumina NextSeq 550 to ~1000X raw coverage.

During apoptosis, cfDNA is released into the bloodstream. Although endonucleases fragment DNA randomly, nucleosome positioning creates biased fragment start and end sites, limiting fragment diversity and causing distinct molecules to appear as duplicates in sequencing data. UMIs, added during library preparation, label individual molecules and enable accurate discrimination between true duplicates and unique fragments.

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Chart comparing duplicate read rates using standard positional duplicate marking versus UMI-aware duplicate marking across 5 ng, 10 ng, and 15 ng cfDNA inputs prepared with Twist Methylated UMI Adapters and the Alliance Pan-Cancer Methylation Panel.
Comparison of EM-seq libraries generated from 10 ng human cfDNA using NEB EM-Seq adapters versus Twist Methylated UMI Adapters, showing sequencing performance after capture with the Twist Alliance Pan-Cancer Methylation Panel.
Illustration showing how cfDNA fragmentation during apoptosis creates sequencing duplicates due to nucleosome positioning, and how unique molecular identifiers (UMIs) label individual DNA molecules to distinguish true duplicates from unique fragments during sequencing analysis.

Superior performance across low-input cfDNA

UMI informed duplicate calling reduces library duplicates by over 15%, leading to an increase in library complexity (25–35%) and mean target coverage (6–8%) compared to standard positional based duplicate calling.

Chart comparing duplicate read rates using standard positional duplicate marking versus UMI-aware duplicate marking across 5 ng, 10 ng, and 15 ng cfDNA inputs prepared with Twist Methylated UMI Adapters and the Alliance Pan-Cancer Methylation Panel.

UMI Performance at Variable cfDNA Mass Inputs 5, 10, or 15 ng of cfDNA were used to generate EM-seq converted libraries with Twist Methylated UMI Adapters following the NEBNext EM-Seq Library Preparation. Libraries were captured with the Twist Alliance Pan-cancer Methylation Panel - 1.5MB using the Targeted Methylation Sequencing Protocol and sequenced on an Illumina Nextseq 550 to 1000X raw coverage. Duplicates were called using GATK MarkDuplicates tool (standard positional method) or called using UMIs with GATK UmiAwareMarkDuplicatesWithMateCigar tool.

High-coverage targeted sequencing using 10 ng cfDNA inputs

EM-seq libraries were generated from 10 ng of human cfDNA using either NEB EM-Seq adapters or Twist Methylated UMI Adapters. Libraries were captured with the Twist Alliance Pan-Cancer Methylation Panel (1.5 Mb) using the Targeted Methylation Sequencing Protocol and sequenced on an Illumina NextSeq 550 to ~1000X raw coverage.

Comparison of EM-seq libraries generated from 10 ng human cfDNA using NEB EM-Seq adapters versus Twist Methylated UMI Adapters, showing sequencing performance after capture with the Twist Alliance Pan-Cancer Methylation Panel.

Schematic of apoptotic cfDNA fragmentation to sequencing coverage.

During apoptosis, cfDNA is released into the bloodstream. Although endonucleases fragment DNA randomly, nucleosome positioning creates biased fragment start and end sites, limiting fragment diversity and causing distinct molecules to appear as duplicates in sequencing data. UMIs, added during library preparation, label individual molecules and enable accurate discrimination between true duplicates and unique fragments.

Illustration showing how cfDNA fragmentation during apoptosis creates sequencing duplicates due to nucleosome positioning, and how unique molecular identifiers (UMIs) label individual DNA molecules to distinguish true duplicates from unique fragments during sequencing analysis.
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Chart comparing duplicate read rates using standard positional duplicate marking versus UMI-aware duplicate marking across 5 ng, 10 ng, and 15 ng cfDNA inputs prepared with Twist Methylated UMI Adapters and the Alliance Pan-Cancer Methylation Panel.

Superior performance across low-input cfDNA

UMI informed duplicate calling reduces library duplicates by over 15%, leading to an increase in library complexity (25–35%) and mean target coverage (6–8%) compared to standard positional based duplicate calling.

Comparison of EM-seq libraries generated from 10 ng human cfDNA using NEB EM-Seq adapters versus Twist Methylated UMI Adapters, showing sequencing performance after capture with the Twist Alliance Pan-Cancer Methylation Panel.

High-coverage targeted sequencing using 10 ng cfDNA inputs

EM-seq libraries were generated from 10 ng of human cfDNA using either NEB EM-Seq adapters or Twist Methylated UMI Adapters. Libraries were captured with the Twist Alliance Pan-Cancer Methylation Panel (1.5 Mb) using the Targeted Methylation Sequencing Protocol and sequenced on an Illumina NextSeq 550 to ~1000X raw coverage.

Illustration showing how cfDNA fragmentation during apoptosis creates sequencing duplicates due to nucleosome positioning, and how unique molecular identifiers (UMIs) label individual DNA molecules to distinguish true duplicates from unique fragments during sequencing analysis.

Schematic of apoptotic cfDNA fragmentation to sequencing coverage.

During apoptosis, cfDNA is released into the bloodstream. Although endonucleases fragment DNA randomly, nucleosome positioning creates biased fragment start and end sites, limiting fragment diversity and causing distinct molecules to appear as duplicates in sequencing data. UMIs, added during library preparation, label individual molecules and enable accurate discrimination between true duplicates and unique fragments.