Leveraging Dielectric Spectroscopy to Rapidly Identifty Temperature Dependent DNA Duplexing

Nucleic acid testing (NAT) measures whether or not a strand of test DNA is duplexed with complementary DNA in solution. These complementary strands bind together at biological temperatures but collaboratively dissociate as temperature increases. However, existing NAT methods can be costly and slow. In order to develop a versatile, rapid measurement procedure for nucleic acid testing we designed a measurement apparatus leveraging a PNAS Vector Network Analyzer to extract dielectric information from biological solutions at various temperature points. Using a coaxial probe inserted into three short-DNA (12BP) solutions, we measured the change in AC signal response resulting from DNA melting and duplexing as mediated by solution temperature shifts. Through comparison with calibration materials (water, IPA, air), we calculate an effective dielectric constant for the DNA solution as a function of temperature. Experiments were verified using molecular dynamics simulations using NAMD, which produced atomistic trajectories that were analyzed for dielectric permittivity.