AVS 53rd International Symposium
    Nanometer-scale Science and Technology Thursday Sessions
       Session NS+BI-ThM

Paper NS+BI-ThM3
Single DNA Molecules Stretched in Electrospun Polymer Fibers

Thursday, November 16, 2006, 8:40 am, Room 2016

Session: Biological and Molecular Applications of Nanoscale Structures
Presenter: L.M. Bellan, Cornell University
Authors: L.M. Bellan, Cornell University
J.D. Cross, Cornell University
E.A. Strychalski, Cornell University
J.M. Moran-Mirabal, Cornell University
H.G. Craighead, Cornell University
Correspondent: Click to Email
We have deposited electrospun polyethylene oxide (PEO) fibers containing isolated single stretched DNA molecules. The ability to stretch single molecules of DNA is desirable for single-molecule sequencing techniques and also allows the study of the behavior of DNA molecules undergoing various forces. Electrospinning is a popular technique for quickly and easily depositing micro- and nanoscale diameter fibers from a variety of materials, and has recently been used in several studies as a method for assembling nanoscale particles and molecules. In the present study, a dilute concentration of fluorescently labeled lambda phage DNA molecules was added to the water solvent used to mix the PEO electrospinning solution. The solution was used to produce isolated nanofibers using the scanned electrospinning technique. The DNA molecules were stretched in-flight in the electrospinning jet and remained stretched when the fluid jet solidified into fibers. These fibers were deposited on coverslips and imaged using fluorescence microscopy. The embedded DNA molecules were seen as single lines of fluorescence ranging from under 3 microns to 19 microns, which is the extended length of the lambda DNA molecule at the base pair to dye labeling ratio used. The variation in length is thought to be due to variations in the electrospinning jet fluid dynamics. By tuning the process parameters we were able to obtain a distribution of stretched lengths with a mode of ~7 microns. We also observed chain scission in some cases. Given the long relaxation time of DNA in the polymer solution and the high strain rates present in electrospinning jets, both stretching and sporadic chain scission are expected. Current work is focused on mechanical manipulation of the resulting fibers and DNA molecules embedded therein.