Probing physical properties of DNA-protein complexes using nanofluidic channels

Karolin Frykholm; Mohammadreza Alizadehheidari; Louise Fornander; Joachim Fritzsche; Jens Wigenius; P. J. Beuning; M. Modesti; F. Persson; Fredrik Westerlund

Probing physical properties of DNA-protein complexes using nanofluidic channels
Paper in proceeding, 2014

We present the use of nanofluidic channels as a tool for determining physical properties of single DNA-protein complexes. By coating the nanochannels with a lipid bilayer we avoid sticking of proteins to the channel walls. RecA is a prokaryotic protein involved in recombination and DNA repair. We study filaments of RecA, bound to both double stranded (ds) and single stranded (ss) DNA. We determine the persistence length of RecA filaments on both dsDNA and ssDNA and obtain values in agreement with the literature. Neither the DNA nor the protein has to be attached to handles or surfaces, and the technique is directly transferable to Lab-on-a-Chip technologies for high throughput measurements in solution.

Lab-on-a-Chip

Nanofluidics

Single DNA molecules

DNA-protein interactions