Collapse of DNA under alternating electric fields

Abstract

Recent studies have shown that double-stranded DNA can collapse in presence of a strong electric field. Here we provide an in-depth study of the collapse of DNA under weak confinement in microchannels as a function of buffer strength, driving frequency, applied electric field strength, and molecule size. We find that the critical electric field at which DNA molecules collapse (10s of kV/cm) is strongly dependent on driving frequency dependent (100 … 800 Hz) and molecular size (20 … 160 kbp), and weakly dependent on the ionic strength (8 … 60 mM). We argue that an apparent stretching at very high electric fields is an artifact of the finite frame time of video microscopy. PACS numbers: 87.14.gk, 36.20.Ey, 82.35.Lr, 82.35.Rs

DNA dielectrophoresis: Theory and applications a review

“…However, Zhou et al. in report that double‐stranded DNA actually collapses in the presence of AC electric fields at frequencies of a few hundred Hertz, rather than being stretched. They argue that the apparent stretching at high fields is an artifact of the finite frame time in video microscopy.…”

The electric field generated by cationic TiO2 nanoparticles can be their key antimicrobial factor

“…Using the comet assay method it has been demonstrated that an electric field up to 200 kV/m induces DNA fragmentation. 30 According to Zhou et al 31 , the critical voltage of the electric field at which DNA molecules collapse is of the order of 10 5 V/m. The driving force of the collapse process is still not fully understood.…”

“…The driving force of the collapse process is still not fully understood. 31 If, indeed, when exposed to TiO 2 NPs, cell death occurs as a result of the influence of the nanoparticles' electric field, this means that the strength of this field should be sufficient to generate the electrical breakdown potential of the bilayer lipid membrane of bacterial cells, that is, on the order of 10 5 -10 6 V/m.…”

“…According to Zhou et al 31 , the critical voltage of the electric field at which DNA molecules collapse is of the order of 10 5 V/m. The driving force of the collapse process is still not fully understood.…”

Collapse of a Confined Polyelectrolyte Chain under an AC Electric Field

“…The last couple of decades have seen an upsurge in nanofluidic-based technologies, which allow manipulation of the structural and transport behavior of various bio-polymers. − In particular, nanochannel electrophoresis has been leveraged extensively in the characterization of artificial gels, separation of long polyelectrolytes (PEs), , and identification of DNA sequences. − The electrophoretic response of a homogeneously charged PE , is rather intriguing due to the electrostatic and hydrodynamic coupling of counterion cloud with the chain, unveiling unusual transport behaviors such as molecular-weight-independent mobility of longer chains, , non-monotonic mobility of shorter chains, − and other counterintuitive structural responses. , Along with the multi-scale coupling of PE in bulk, the presence of strong spatial confinement brings further addendum to its characteristic features such as elongation, − suppression of diffusion, − cross-streamline migration, , and mobility reversal . Strong temporally varying fields may lead to further behavioral complexities as exemplified in recent experiments, − where a DNA molecule undergoes large-scale structural collapse in an AC field. However, the broader consensus is that a PE chain stretches under a homogeneous field as reported in several electrophoresis experiments ,− and simulation studies. ,,− …”