---
title: "What is Fiber-seq?"
slug: "what-is-fiber-seq"
updated: 2025-11-11T13:00:01Z
published: 2025-11-11T13:00:01Z
canonical: "support.epicypher.com/what-is-fiber-seq"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://support.epicypher.com/llms.txt
> Use this file to discover all available pages before exploring further.

# What is Fiber-seq?

CUTANA™ Fiber-seq is a long-read, multiomic sequencing assay that simultaneously profiles chromatin accessibility, DNA methylation, and genetic variants. Unlike short-read methods, Fiber-seq provides base-resolution chromatin maps in repetitive and structurally complex regions of the genome. For more background, see the [groundbreaking 2020 Nature article by Andrew Stergachis introducing Fiber-seq](https://www.science.org/doi/10.1126/science.aaz1646).

**Key Benefits:**

- Multiomic profiling in a single assay
- Antibody-free, PCR-free workflow
- Compatible with PacBio and Oxford Nanopore (ONT) sequencing
- Resolves nucleosomes, transcription factor binding, and RNA polymerase footprints at near-nucleotide precision
- Simple upstream workflow (<3 hours before library prep)

Powered by Hia5, the highest-activity N6-adenine methyltransferase (6mA MTase), Fiber-seq enables fast and efficient labeling of accessible DNA prior to long-read sequencing. Purchase [Hia5 (EpiCypher 15-1032-8rxn / EpiCypher 15-1032-24rxn)](https://www.epicypher.com/product/cutana-hia5-for-fiber-seq/) exclusively from EpiCypher for DIY Fiber-Seq, or use our Fiber-Seq Kit ([EpiCypher 14-2001-8rxn or 14-2001-24rxn](https://www.epicypher.com/product/cutana-fiber-seq-kit/)) for an integrated solution that takes you from nuclei isolation through gDNA purification.

![](https://cdn.document360.io/1fc69f91-cf1e-45ab-bc51-4063eb80e37c/Images/Documentation/image(6).png)Figure 1: Fiber-seq simultaneously detects open chromatin (marked by 6mA) and DNA methylation (5mC) in human leukemia (K562) cells. ATAC-seq and CTCF CUT&RUN data are shown for comparison. Each horizontal line in the Fiber-seq panels represents a single long read, providing single-molecule data. Data from 60 individual DNA molecules are shown.