Dielectrophoretic stretching of DNA tethered to a fiber tip.
In this work, we studied the stretching of λ phage DNA molecules immobilized on an optical fiber tip attached to a force sensitive tuning fork under ac electric fields. We designed a two electrodes stretching system in a small chamber: one is a gold-coated optical fiber tip electrode, and the other is a gold-coated flat electrode. By applying a dielectrophoretic (DEP) force, the immobilized λ DNA molecules on the tip are stretched and the stretching process is monitored by a fluorescent microscope. The DNA stretching in three-dimensional space is optimized by varying electrode shape, electrode gap distance, ac frequency, and solution conductivity. By observing the vibrational amplitude change of a quartz tuning fork, we measured the effects due to Joule heating and the DEP force on the tethered DNA molecules in solution. This work demonstrates a method to manipulate and characterize immobilized λ DNA molecules on a probe tip for further study of single DNA molecules.
Department of Physics, University of Arkansas, Fayetteville AR 72701, USA.
Changbae
C
Hyun
Harpreet
H
Kaur
David S
DS
McNabb
Jiali
J
Li
D000818:Animals; D010582:Bacteriophage lambda / Q000235:genetics; D003198:Computer Simulation; D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D004566:Electrodes; D055590:Electromagnetic Phenomena; D006046:Gold / Q000737:chemistry; D006801:Humans; D055100:Optical Fibers; D052898:Optical Tweezers
D006046:Gold; D004247:DNA