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Updated: Jul 7, 2026
Atomic Force Microscopy Investigations of DNA Lesion Recognition in Nucleotide Excision Repair
Published on: May 24, 2017
Accurate DNA fragment sizing by capillary electrophoresis with laser-induced fluorescence array for detection of
Erwin V Fundador1, Dharamainder Choudhary, John B Schenkman
1Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, USA.
Abstract:
Cancer has been linked to mutations within specific codons in genes that code for critical biomolecules such as tumor suppressor proteins (e.g., p53). Activated metabolites like benzo[a]pyrenediol epoxide act on preferred nucleotide sequences of DNA, and such mutations have been identified in cancers. DNA reaction site identification depends on accurate analysis of oligonucleotide fragment sizes produced by strand breakage at the damaged sites. Herein, we report a new method for DNA fragment sizing using capillary electrophoresis with laser-induced fluorescence detection (CE-LIF). Absolute sizing accuracy and speed are achieved by utilizing a CE-LIF array with two-color fluorescence detection. Accuracy depends on correcting results with commercial standards by referring them to primary standards with the same sequences and identical labels as sample fragments. The method is demonstrated by detection of a [...GGCGCGCAG...] G reaction site for styrene oxide on an oligonucleotide representing the CYP1B1 gene. This approach avoids the need for radioactive isotopes and is less labor intensive and faster than the alternative PAGE with (32)P end labeling.
Insights
A new capillary electrophoresis method accurately sizes DNA fragments, aiding cancer mutation detection. This faster, isotope-free technique identifies DNA damage sites in genes like CYP1B1.
Area of Science:
- Molecular Biology
- Genetics
- Analytical Chemistry
Background:
- Cancer is linked to gene mutations, particularly in tumor suppressor genes.
- Environmental toxins and their metabolites can cause DNA damage at specific nucleotide sequences.
- Accurate identification of DNA reaction sites is crucial for understanding cancer development.
Purpose of the Study:
- To develop a novel, accurate, and rapid method for DNA fragment sizing.
- To identify DNA reaction sites associated with carcinogen exposure.
- To provide an alternative to labor-intensive and hazardous radioactive labeling methods.
Main Methods:
- Utilized capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) array.
- Employed two-color fluorescence detection for absolute sizing accuracy and speed.
- Validated accuracy by correcting commercial standards against primary standards with identical sequences and labels.
Main Results:
- Successfully demonstrated the detection of a specific DNA reaction site ([...GGCGCGCAG...] G) for styrene oxide.
- The oligonucleotide analyzed represented a sequence from the CYP1B1 gene.
- Achieved high accuracy and speed in DNA fragment sizing.
Conclusions:
- The developed CE-LIF method offers a precise and efficient way to identify DNA damage sites.
- This technique avoids the use of radioactive isotopes, making it safer and less labor-intensive.
- The method is faster than traditional gel electrophoresis techniques like PAGE with (32)P end labeling.
