---
title: "Why do I have high read duplication rates in my CUT&Tag data?"
slug: "high-read-duplicates-cut-and-tag"
updated: 2024-12-09T14:58:20Z
published: 2024-12-09T14:58:20Z
canonical: "support.epicypher.com/high-read-duplicates-cut-and-tag"
---

> ## 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.

# Why do I have high read duplication rates in my CUT&Tag data?

High read duplicate rates are common in CUT&Tag due to assay sensitivity and extremely low background.

In general, duplication rates are higher for low abundant PTMs (H3K4me3; 50-70%) compared abundant PTMs (H3K27me3 positive control; 10-30%). High read duplicate rates are also common when profiling from low inputs, where additional PCR cycles and deeper sequencing are need to capture read diversity.

Based on EpiCypher's CUT&Tag optimization studies and analyses of published datasets, duplication rates below 70% do not impact sequencing data quality. Duplicates can be assessed and removed using Picard ([broadinstitute.github.io/picard](http://broadinstitute.github.io/picard)).

However, if duplications rates are a concern, there are troubleshooting options, as outlined in [this article](https://support.epicypher.com/docs/troubleshooting-cut-and-tag-sequencing#high-read-duplication-rates).