Related Experiment Video
Updated: Jul 7, 2026

Visualizing and Quantifying Endonuclease-Based Site-Specific DNA Damage
Published on: August 21, 2021
Spontaneous DNA repair increases during hemodialysis
Michal Herman1, Yaacov Ori, Avry Chagnac
1Departments of Nephrology and Hypertension, Rabin Medical Center, Petah-Tikva, Israel.
Background:
Hemodialysis (HD) patients are subjected to increased oxidative stress. Oxidative stress causes DNA damage, which may be repaired by a DNA repair system. 'Spontaneous DNA repair' expresses DNA repair of in vitro unstimulated cells. The aim of the study was to evaluate the effect of one HD session on spontaneous DNA repair in peripheral blood mononuclear cells (PBMC).
Methods:
PBMC were separated from blood samples for the determination of spontaneous DNA repair, measured by (3)H-thymidine incorporation, before and immediately after one HD session. Percent double-stranded DNA (ds-DNA) was measured by the fluorometric assay of DNA unwinding (FADU).
Results:
DNA repair increased significantly following HD. To examine if this increase was caused by newly produced DNA damage, we studied the effect of HD on percent ds-DNA in PBMC. HD significantly reduced percent ds-DNA, indicating increased DNA breakage. By repeating FADU in the presence of formamidopyrimidine-DNA glycosylase (Fpg), which nicks DNA at oxidized purine sites, we could show that the increased DNA damage was caused by oxidation.
Conclusion:
Spontaneous DNA repair increases during HD in response to an increase in DNA damage induced by oxidative stress.
Related Concept Videos
Overview of DNA Repair
Chemically...
Overview of DNA Repair
Chemically...
Fixing Double-strand Breaks
Fixing Double-strand Breaks
Spontaneous and Induced Mutations
Nucleotide Excision Repair
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...

