DNA FIBERS BY ELECTROSPINNING

Thin fibers of calf thymus Na-DNA were electrospun from aqueous soluti ons with concentrations from 0.3% to 1.5%. In electrospinning, a high voltage is used to create an electrically charged jet of liquid soluti on, which dries to leave a polymer fiber. The electrospun DNA fibers h ave diameters around 50 to 80 nm. The diameter of the electrospun fibe rs is an order of magnitude or more smaller than that of previously re ported fibers. The DNA fibers were observed by optical microscopy, sca nning electron microscopy, and transmission electron microscopy. Bead- like structures were observed on many of the fibers. During electrospi nning a process called splaying causes the jet to split longitudinally into two smaller jets, which split again, repeatedly, until the very small diameter fibers are formed. The small-diameter fibers are transp arent in ordinary 100 kV electron microscopes. Fibers can be spun from samples of DNA as small as 1 mg.