Forster Resonance Energy Transfer and Laser Fluorescent Analysis of Defects in DNA Double Helix

TL;DR

This paper demonstrates a real-time laser fluorescence spectroscopy method using FRET to analyze DNA double helix defects caused by metal ions, nanoparticles, and stress factors, providing detailed insights into DNA damage.

Contribution

The study introduces a novel FRET-based fluorescence technique for microanalysis of DNA defects, with experimentally validated FRET radii and concentration estimations under various stress conditions.

Findings

FRET radii estimated at 3.9 nm, matching theoretical 3.5 nm.

Method quantifies DNA damage levels after stress exposure.

Allows comparison of DNA from different sources and damage states.

Abstract

Real time laser induced fluorescence spectroscopy usage for microanalysis of DNA double helix defects is shown. The method is based on Forster resonance energy transfer (FRET) in intercalator-donor pair (acridine orange as a donor and ethidium bromide as an acceptor). Transition metal ions such as Cu(II), Cu(I), Ag(I), silver nanoparticles (AgNPs), photo- and thermo effects were used to cause double helix defects in DNA. FRET radii were experimentally estimated in background electrolyte solution (0.01 M NaNO3) and proved to be 3.9 +- 0.3 nm and the data are in satisfactory agreement with the theoretically calculated value Ro = 3.5 +- 0.3 nm. Concentration of DNA sites, exposed to Cu(II), Cu(I), Ag(I) ions, AgNPs impact as well as laser irradiation ({\lambda} = 457 nm) and temperature, which are applicable for intercalation, were estimated in relative units. FRET method allows to estimate the concentration of double helix areas with high quality stability applicable for intercalation in DNA after it was subjected to stress effect. It gives the opportunity to compare DNAs of 1) different origin; 2) with various damage degrees; 3) being in various functional state.