Sensing of DNA conformation based on change in FRET efficiency between laser dyes

• Effect of DNA conformation on fluorescence resonance energy transfer (FRET) between two laser dyes in layer by layer film.
• Increase in pH or temperature cause the denaturation of DNA followed by coil formation of single stranded DNA.
• Change in FRET efficiency due to change in DNA conformation.
• Idea about DNA conformation from the change in FRET efficiency.

This communication reports the effect of DNA conformation on fluorescence resonance energy transfer (FRET) efficiency between two laser dyes in layer by layer (LbL) self assembled film. The dyes Acraflavine and Rhodamine B were attached onto the negative phosphate backbones of DNA in LbL film through electrostatic attraction. Then FRET between these dyes was investigated. Increase in pH or temperature causes the denaturation of DNA followed by coil formation of single stranded DNA. As a result the FRET efficiency also changed along with it. These observations demonstrated that by observing the change in FRET efficiency between two laser dyes in presence of DNA it is possible to detect the altered DNA conformation in the changed environment.

Attachment of FRET pair (Acf + RhB) with (a) DNA double helix structure, (b) DNA denatured form, (c) DNA coil form and variation of FRET efficiency.Figure optionsDownload as PowerPoint slide