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Epigenetics

All-in-one multiomic insights with methylation and chromatin structure detection

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Epigenetics and DNA modifications with 5-base HiFi sequencing

Epigenetics is about understanding how gene activity changes without altering the DNA sequence itself. Powered by advanced methylation algorithms, PacBio 5-base sequencing simultaneously detects DNA sequences and multiple DNA modifications from native DNA in a single assay. This integrated approach unites long-read phasing and multiomic analysis for a faster, more complete view of biology. Combine this approach with Fiber-seq to map single chromatin fibers and uncover footprints, nucleosomes, variants, and methylation—all in one streamlined assay.

Epigenetics on PacBio at a glance

Epigenetics on PacBio Whole genome bisulfite sequencing (WGBS) ATAC-seq
Genetic variants (e.g., SNVs, INDELs, SV) Very limited X
Methylation (5mCpG) Limited (mATAC-seq or ATAC-me)
Avg. read lengths 10–20 kb ~150 bp PE ~ 50–150 bp PE
Genome mapping Highest MAPQ in both unique and non-unique sequence Low MAPQ due to bisulfite treatment Unique and accessible regions only
Haplotype-phasing X X
Single-molecule X X
Open chromatin + Fiber-seq X
Nucleosome positions + Fiber-seq X X
TF footprint + Fiber-seq X Limited; requires high coverage (>200M PE)
All-in-one assay consolidation with Fiber-seq

Video

See the power of HiFi Epigenetics

In this overview video, explore how PacBio highly accurate long reads enable direct detection of base modifications, delivering comprehensive insights into methylation patterns alongside genetic variation. Learn how a single HiFi workflow can illuminate gene regulation, cell differentiation, and disease mechanisms, without the need for additional assays.

Go beyond 5-base sequencing by detecting a broader range of DNA modifications

HiFi long-read sequencing captures DNA methylation by measuring subtle differences in polymerase kinetics during sequencing. As new machine learning models expand to detect additional base modifications (e.g., 5hmC), the power of HiFi sequencing continues to grow—making HiFi sequencing a technology that shapes and evolves with the epigenetics field.

With HiFi, you can:

  • Directly link genetic variation with changes in methylation
  • Access challenging regions of the genome that defy short reads
  • See allele-specific differences in methylation patterns with haplotype phasing
  • Detect parental imprinting

Epigenetics 101 blog

“And now, with the introduction of Fiber-seq to characterize nucleosome positioning, the ability to tackle these applications with Vega is a game changer, especially for some of the bigger questions we haven’t yet been able to address –– like how does neuronal development work? How is the immune system triggered in response to certain stimuli? How is regeneration controlled? These are all things we can explore with Vega.”

Andor Kiss from Miami University in Oxford, Ohio

Single chromatin fiber sequencing for high-resolution views of the epigenome

Fiber-seq maps chromatin features at single-molecule resolution on every HiFi read—capturing genetic variation, chromatin accessibility, nucleosome positioning, CpG methylation, and transcription factor binding in one unified assay. This comprehensive, multiomic view reveals haplotype-specific gene regulation and chromatin dynamics that would otherwise require multiple short-read assays.

Key capabilities:

  • Single-molecule chromatin accessibility
  • Near base-pair nucleosome resolution
  • CpG methylation detection
  • Transcription factor (TF) footprinting
  • Haplotype phasing for chromatin accessibility
  • Direct link between genetic variation and gene expression

Download Fiber-Seq app note

Epigenetics in action

DNA-m6A calling and integrated long-read epigenetic and genetic analysis with fibertools

Here, we introduce fibertools, a state-of-the-art toolkit that features a semisupervised convolutional neural network for fast and accurate identification of m6A-marked bases using Pacific Biosciences single-molecule long-read sequencing.

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Synchonized long-read genome, methylome, epigenome, and transcriptome for resolving a Mendelian condition

Resolving the molecular basis of a Mendelian condition remains challenging owing to the diverse mechanisms by which genetic variants cause disease. This article highlights the utility of synchronized long-read multi-omic profiling for mechanistically resolving complex phenotypes.

View article

Stylized RNA image on blue/teal gradation

Breakthrough discoveries in genomics, transcriptomics and epigenomics with HiFi long-read sequencing

This workshop delves into the forefront of genomics research! Discover how innovative researchers are leveraging the extraordinary accuracy and comprehensive coverage of HiFi sequencing to drive groundbreaking insights into the intricate world of genetic variation, RNA splicing, and epigenetic gene regulation.

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Did you know we have over 10,000 articles, reports, papers, and videos related to epigenetic research?

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Epigenetic sequencing workflow at a glance

Standard library prep

  • No bisulfite or other enzymatic treatment

Fiber-seq library prep

  • CUTANA Fiber-seq from EpiCypher
  • PacBio standard library prep

Library prep kits

Standard library prep

  • Simultaneous detection of base sequence (A, C, G, and T) and epigenetic modifications – no additional sequencing experiments need

SMRT sequencing

img laptop smrt link

Analysis

  • On-instrument barcoding and methylation calling
  • View methylation calls in IGV
  • Pb-CpG-tools for methylation pileups
  • Fibertools for Fiber-seq data analysis and inferring regulatory elements

Common questions about PacBio epigenetic sequencing

PacBio HiFi sequencing measures real-time polymerase kinetics, tiny differences in the timing as bases are incorporated. Methylated bases change this pattern, allowing the system to identify modifications such as 5mC or 6mA (Fiber-seq) directly from native DNA, without bisulfite conversion or amplification.

  • In eukaryotes, PacBio 5-base sequencing calls 5mC in CpG context directly and 6mA for the Fiber-seq assay.
  • In microbes, PacBio can detect 4mC, 5mC, and 6mA using trained kinetic models.
  • Ongoing model development aims to expand detection capabilities across more modification types. 5hmC detection will be available with SPRQ-Nx chemistry in 2026.

  • HiFi sequencing simultaneously detects base sequences and epigenetic modifications in a single experiment.
  • Fiber-seq (6mA) requires an upfront treatment of isolated nuclei with the non-specific adenine methyltransferase Hia5 followed by standard PacBio library preparation.

5-base sequencing means detecting the four standard DNA bases (A, C, G, T) plus one additional base modification: the most common form of methylated cytosine (5mC). This approach provides both genetic and epigenetic information in one sequencing experiment. Unlike short-read technologies, 5-base sequencing comes standard on PacBio HiFi systems and doesn’t require any special library preparation.

Bisulfite sequencing converts all unmethylated cytosines, requires PCR, and fragments DNA. This leads to uneven coverage and confounds read mapping. PacBio HiFi reads offer more reliable coverage across the entire genome leading to more 5mCpG calls compared to WGBS. Moreover, the read length of HiFi sequencing enables de novo DNA methylation analysis in sites that may not be found in the reference.

Yes. Every HiFi read represents a multi-kilobase single molecule of DNA. Methylation calls are included in the same reads and are phased with SNPs and structural variants, revealing allele-specific methylation patterns that are invisible to short-read methods.

  • HiFi sequencing reveals chromatin accessibility through Fiber-seq, a single chromatin fiber sequencing method. Fiber-seq uses a non-sequence-specific adenine methyltransferase (Hia5) to label accessible regions within intact chromatin.
  • The 6mA labels are then detected during standard sequencing allowing for accessible open chromatin regions, nucleosome positions, and TF occupancy to be map across the genome.

  • Methylation signatures are called on-instrument during primary data analysis and come included in every sequencing run.
  • Alternatively, methylation calling can be performed off-instrument by saving the kinetic data and using the Jasmine software tool
  • pb-CpG-tools can be used to generate site methylation probabilities from mapped HiFi reads.
  • Fibertools and the FIRE pipeline can be used to interact with Fiber-seq data and infer regulatory elements (accessible regions) and nucleosome occupancy.

Start by exploring publicly available HiFi datasets or reach out to PacBio or certified partners for a pilot methylome study. Our team can guide you through system setup, sample preparation, and analysis workflows tailored to your research goals.

FEATURED LONG-READ SEQUENCING SYSTEMS

5-base genome sequencing is now possible. With PacBio long-read sequencers you can gain immediate access to the epigenome with no special workflow or data processing steps required.

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