Related Experiment Video
Updated: Jul 10, 2026
Visualization of UV-induced Replication Intermediates in E. coli using Two-dimensional Agarose-gel Analysis
Published on: December 21, 2010
Efficiency of pyrimidine dimer formation in Escherichia coli across UV wavelengths
1Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708-0287, USA.
Aims:
Inactivation of Escherichia coli as a function of ultraviolet (UV) wavelength was investigated by using the endonuclease-sensitive site (ESS) assay to quantify pyrimidine dimer formation.
Methods And Results:
Ultraviolet dose-response curves were determined based on both log reduction in colony-forming units (CFU) and endonuclease-sensitive sites per kb DNA (ESS/kb) for monochromatic 254-nm low-pressure (LP) UV, polychromatic medium-pressure (MP) UV, 228 and 289-nm UV irradiation. UV irradiation from LP and MP UV sources were approx. equal in both CFU reduction and pyrimidine dimer formation at all UV doses studied; 228-nm irradiation was less effective than LP or MP, and 289-nm irradiation was the least effective in both CFU reduction and pyrimidine dimer formation. These results are in qualitative agreement with the absorption spectrum of pyrimidine bases in DNA. Results indicated an approx. linear relationship between ESS/kb and log CFU reduction.
Conclusions:
Formation of pyrimidine dimers in genomic DNA is primarily responsible for UV inactivation of E. coli.
Significance And Impact Of The Study:
This work contributed to fundamental understanding of UV disinfection and aids in UV reactor design.
