# Tn5-Labeled DNA-FISH: An Optimized Probe Preparation Method for Probing Genome Architecture

## TL;DR

This paper introduces an improved DNA-FISH method using Tn5 transposomes to study genome architecture at high resolution.

## Contribution

The novel Tn5-labeled DNA-FISH method allows efficient and cost-effective preparation of DNA probes for studying genome spatial organization.

## Key findings

- The Tn5-labeled DNA-FISH method enables probe preparation for genomic regions as small as 4 kb.
- The method simultaneously fragments and labels DNA in a single step using a self-assembled Tn5 transposome.
- It allows visualization of both endogenous and exogenous genomic loci at kilobase resolution.

## Abstract

Three-dimensional genome organization reveals that gene regulatory elements, which are linearly distant on the genome, can spatially interact with target genes to regulate their expression. DNA fluorescence in situ hybridization (DNA-FISH) is an efficient method for studying the spatial proximity of genomic loci. In this study, we developed an optimized Tn5 transposome-based DNA-FISH method, termed Tn5-labeled DNA-FISH. This approach amplifies the target region and uses a self-assembled Tn5 transposome to simultaneously fragment the DNA into ~100 bp segments and label it with fluorescent oligonucleotides in a single step. This method enables the preparation of probes for regions as small as 4 kb and visualizes both endogenous and exogenous genomic loci at kb resolution. Tn5-labeled DNA-FISH provides a streamlined and cost-effective tool for probe generation, facilitating the investigation of chromatin spatial conformations, gene interactions, and genome architecture.