Tohoku University Scientists Uncover Hidden DNA Damage Mechanism Caused by Singlet Oxygen Exposure

Scientists discover that singlet oxygen removes DNA building blocks, creating abasic sites. This hidden mechanism was found using advanced mass spectrometry.

By: AXL Media

Published: Apr 24, 2026, 6:25 AM EDT

Source: Information for this report was sourced from EurekAlert!

The Vulnerability of Genetic Building Blocks

Human genetic material faces constant degradation from environmental triggers like light and internal factors such as inflammation. These stressors generate oxidative damage that affects both DNA and RNA, contributing to accelerated aging and the development of diseases like cancer. While scientists have known for decades that guanine is the most vulnerable of the four DNA building blocks, new research suggests that current testing methods have overlooked a significant portion of this damage. Assistant Professor Yuuhei Yamano from the Institute of Multidisciplinary Research for Advanced Materials noted that these limitations have left a critical blind spot in our understanding of how genetic material is compromised.

Singlet Oxygen and the Creation of Abasic Sites

By utilizing a photocatalyst and light to simulate oxidative stress, the research team discovered the formation of abasic sites, which are essentially gaps where a DNA letter has been completely removed. This process is driven by singlet oxygen, a highly reactive molecule that attacks guanine residues directly. The study reveals that this type of damage is not a rare occurrence but rather one of the primary forms of DNA degradation. Unlike previously recognized types of oxidation that merely alter the guanine structure, this mechanism results in the total loss of the building block, significantly altering the integrity of the genetic code.

Bypassing the Limitations of Traditional Detection

The discovery was made possible by shifting away from standard analytical techniques that rely on breaking DNA into small fragments for ultraviolet light analysis. Instead, the Tohoku University team employed a sophisticated mass spectrometry approach that allows for the direct examination of DNA in its intact state. According to Assistant Professor Yamano, this transition was essential for identifying damage that disappears or becomes unobservable when DNA is fragmented. By analyzing the genetic material as a whole, the researchers were able to quantify the presence of abasic sites that had remained hidden from the scientific community for decades.