A Breakthrough in WGBS: The First Methylation-Safe Fragmentation Strategy

Whole-genome bisulfite sequencing (WGBS) is the gold standard for DNA methylation analysis, widely used in cancer research, biomarker discovery, and developmental biology. However, formalin-fixed paraffin-embedded (FFPE) clinical samples often yield highly degraded and damaged DNA in limited amounts (DIN as low as 1.8). Traditional mechanical fragmentation and bisulfite conversion worsen DNA damage, causing low library yield, high duplication rates, and poor CpG coverage.

Recent studies show that combining enzymatic DNA fragmentation with enzymatic methylation conversion significantly improves results. Even with just 10 ng input DNA, this approach generates high-quality libraries with better mapping rates and CpG coverage.

Limitations of Conventional Fragmentation Methods

DNA fragmentation is a critical step in methylation library preparation. Traditional approaches present two major limitations. 

1. Mechanical fragmentation: expensive and damaging

Acoustic shearing systems require specialized instruments and consumables, making experiments costly and difficult to scale. In addition, the physical shearing process can cause significant DNA loss, which is particularly problematic for low-input or degraded FFPE samples.

2. Conventional enzymatic fragmentation: methylation bias

Some standard enzymatic fragmentation systems can alter or interfere with 5-methylcytosine (5-mC) sites, potentially introducing false-negative methylation signals and compromising the accuracy of downstream methylation analysis.

Why Methylation-Compatible Enzymatic Fragmentation Matters

A methylation-compatible enzymatic fragmentation strategy can address these limitations by enabling efficient DNA fragmentation without affecting methylation marks.

Key Advantages

Feature	Benefit
Methylation-preserving chemistry	Maintains accurate 5-mC signals and avoids false negatives
Gentle enzymatic fragmentation	Minimizes DNA damage and sample loss
Compatible with low-input DNA	Works with inputs as low as 5–10 ng
Flexible fragment control	Generates fragments from ~100–1500 bp
Automation friendly	Eliminates the need for acoustic shearing instruments

Yeasen’s Hieff^TM UltraShear Methylation Fragmentase (Cat# 12218ES): Purpose-Built for Epigenomics

As the first Chinese developer of a methylation-dedicated fragmentase, Yeasen offers a complete solution optimized for both enzymatic and bisulfite-based workflows.

1. Preserves Native Methylation Marks

No modification of 5mC sites—methylation levels match ultrasonication, unlike conventional enzymes that distort results. 

Figure 1. Impact of different fragmentation methods on DNA methylation profiles.

gDNA from 293T cells, mouse, and rice was fragmented using conventional enzymatic fragmentation, ultrasonication (Covaris), or Yeasen’s UltraShear Methylation Fragmentase (Cat# 12218ES). Methylation levels were assessed by whole-genome bisulfite sequencing (WGBS). Results show that methylation patterns generated with 12218ES closely match those from ultrasonication, while conventional enzymatic fragmentation significantly distorts methylation signals, leading to underestimation of 5-methylcytosine (5mC) levels. This confirms that 12218ES preserves native methylation marks without bias.

2. Ultra-Low DNA Damage, High Yield

Gentle enzymatic cleavage minimizes loss. Outperforms sonication in library yield, especially with 10 ng inputs or FFPE DNA.

Figure 2. Comparison of library yield between ultrasonication and methylation-specific enzymatic fragmentation.

Library yields were evaluated using 10 ng of input genomic DNA fragmented by either ultrasonication or Yeasen’s Hieff® UltraShear Methylation Fragmentase (Cat# 12218ES). The enzymatic method resulted in significantly higher library yields compared to ultrasonication, particularly at low input amounts. This demonstrates that 12218ES causes minimal DNA damage and maximizes sample utilization, making it ideal for methylome analysis of limited or degraded samples such as FFPE.

3.Simple, Equipment-Free & Automatable

Incubate at 37°C for 10–45 min to achieve 100–1500 bp fragments. No special instruments needed—ideal for high-throughput labs.

5. High-Efficiency Library Prep Across FFPE Quality Grades

Delivers superior methylation recovery in low-quality FFPE samples compared to sonication-based methods, while maintaining comparable performance on high-quality FFPE.

Fragmentation Conditions (using Enzyme #12218):

• High-quality FFPE: 4°C 1 min → 37°C 15 min → 65°C 20 min → hold at 4°C (lid: 105°C)
• Low-quality FFPE: 4°C 1 min → 37°C 5 min → 65°C 20 min → hold at 4°C (lid: 105°C)

Workflow:

• Library prep: #12214 Methyl-Seq Dual-Index Kit
• Bisulfite conversion: #12229 Ultra-Fast Methyl Conversion Kit
• Spiked-in controls: 0.5–1% Lambda DNA & pUC19

Sample Quality	Input (ng)	Fragmentation	Yield (ng)	Q30 (%)	GC (%)	Unique Mapping Rate (%)	Duplication (%)	CpG Methylation (%)	Lambda Conversion Rate (%)	pUC19 CpG Methylation (%)
High-quality FFPE	200	12218	2144	98.16	21.71	88.9	16.21	48.9	99.87	95.3
Low-quality FFPE	50		243	98.29	22.54	72.3	9.81	76.0	99.85	95.7
High-quality FFPE	200		1800	97.98	21.36	89.7	15.78	48.2	99.87	94.5
Low-quality FFPE	50		214.5	98.23	22.50	68.8	10.79	74.3	99.84	95.2
High-quality FFPE	200	Sonication	1712	97.86	20.96	84.9	16.18	47.5	99.87	94.9
Low-quality FFPE	50		318	98.10	22.04	58.1	11.56	70.7	99.86	94.6

Related Product

Product Name	Cat. No.	Application
HieffTM Superfast DNA Methylation Bisulfite Kit	12228ES	Column-based DNA methylation conversion
HieffTM Mag Superfast DNA Methylation Bisulfite Kit	12229ES	Magnetic bead-based DNA methylation conversion
Hieff NGSTM dsDNA Methyl Library Prep Kit for Illumina	12214ES	DsDNA methylation library prep for Illumina
HieffTM UltraShear	12218ES	Enzyme-based methylation fragmentation