# Evaluation of two new antibodies for recognition of CldU in DNA fiber assay applications

## TL;DR

The paper introduces two new antibodies for detecting CldU in DNA fiber assays, which can improve the study of DNA replication and damage.

## Contribution

The paper introduces and validates two new CldU-reactive antibodies for DNA fiber assays.

## Key findings

- One of the new antibodies can be paired with a common IdU-reactive antibody.
- The new antibody produces quantitatively similar results to the previously used BU1/75 antibody.
- The new reagents increase the versatility of DNA fiber assays for replication research.

## Abstract

DNA fiber assays are indispensable tools for studying DNA damage and replication stress responses
in vivo
at the single replication fork level. These assays typically rely on antibodies recognizing IdU and CldU. Historically, the availability of CldU-reactive antibodies has been limited to one reagent (clone BU1/75(ICR1)). We validated two alternative antibodies for CldU detection in DNA fiber assays. One of these antibodies can be readily paired with a common IdU-reactive antibody, and we confirmed that it produces quantitatively similar CldU track length results vis-à-vis the BU1/75 antibody. The new reagents should boost versatility of DNA fiber assays, facilitating DNA replication research.