Major
Chemistry
Research Abstract
Electrostatic melting is an electrochemical tool that can be used to analyze the stability of the DNA double helix, allowing for the detection of various mutations in double stranded DNA (dsDNA).1 Here we explore the effect of electrochemical double layer formation on the electrostatic melting of dsDNA in an effort to better understand the mechanism of the aforementioned category of melting. Previous studies from our lab have shown that electrostatic melting curves can be used to distinguish between duplexes that are fully complementary and duplexes that contain a single mismatch.2 Electrostatic melting is assumed to result from the electrostatic repulsion between the sugar-phosphate backbone and a negatively charged electrode. Rant et al. have shown that when the potential on the electrode is pulsed between an attractive and repulsive potential, at frequencies higher than a critical value, the ions in solution are unable to react quickly enough to form the double layer.3 From this, we hypothesize that we can obtain better insight on the mechanism of electrostatic DNA melting by replacing the melting step of our standard melting procedure with a fast potential pulse routine that alternates between a potential at which melting will occur and a potential too weak for melting to occur. By varying the frequency of this fast pulse melting, we can determine the effect of double-layer formation. The initial results of this research, presented here, suggest that the melting rate remains constant regardless of frequency, which implies that the mechanism of electrostatic DNA melting is not due to the generation of the electric field. This indicates that the melting mechanism is not purely electrostatic, contrary to what is commonly assumed.
Faculty Mentor/Advisor
Ryan West
Included in
Determining the Impact of Double-Layer Formation on Electrostatic DNA Melting
Electrostatic melting is an electrochemical tool that can be used to analyze the stability of the DNA double helix, allowing for the detection of various mutations in double stranded DNA (dsDNA).1 Here we explore the effect of electrochemical double layer formation on the electrostatic melting of dsDNA in an effort to better understand the mechanism of the aforementioned category of melting. Previous studies from our lab have shown that electrostatic melting curves can be used to distinguish between duplexes that are fully complementary and duplexes that contain a single mismatch.2 Electrostatic melting is assumed to result from the electrostatic repulsion between the sugar-phosphate backbone and a negatively charged electrode. Rant et al. have shown that when the potential on the electrode is pulsed between an attractive and repulsive potential, at frequencies higher than a critical value, the ions in solution are unable to react quickly enough to form the double layer.3 From this, we hypothesize that we can obtain better insight on the mechanism of electrostatic DNA melting by replacing the melting step of our standard melting procedure with a fast potential pulse routine that alternates between a potential at which melting will occur and a potential too weak for melting to occur. By varying the frequency of this fast pulse melting, we can determine the effect of double-layer formation. The initial results of this research, presented here, suggest that the melting rate remains constant regardless of frequency, which implies that the mechanism of electrostatic DNA melting is not due to the generation of the electric field. This indicates that the melting mechanism is not purely electrostatic, contrary to what is commonly assumed.
