Blowing DNA bubbles.
We report here experimental observations which indicate that topologically or covalently formed polymer loops embedded in an ultrathin liquid film on a solid substrate can be "blown" into circular "bubbles" during scanning force microscopy (SFM) imaging. In particular, supercoiled vector DNA has been unraveled, moved, stretched, and overstretched to two times its B-form length and then torn apart. We attribute the blowing of the DNA bubbles to the interaction of the tapping SFM tip with the ultrathin liquid film.
Severin
N
N
Department of Physics, Humboldt University Berlin, Newtonstr. 15, D-12489 Berlin, Germany. nikolai.severin@physik.hu-berlin.de
Zhuang
W
W
Ecker
C
C
Kalachev
A A
AA
Sokolov
I M
IM
Rabe
J P
JP
D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force / Q000379:methods; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry; D012680:Sensitivity and Specificity; D013499:Surface Properties
D008567:Membranes, Artificial; D011137:Polystyrenes; C003321:polystyrene sulfonic acid; D004247:DNA