Dynamic force microscopy imaging of plasmid DNA and viral RNA.
Plasmid DNA and viral RNA were imaged in a liquid environment by dynamic force microscopy (DFM) and fine structures of DNA with heights of 1.82+/-0.66 nm were obtained in topographical images. In simultaneously acquired phase images, DNA could be imaged with better contrast at lower imaging forces. By splitting the cantilever oscillation signal into lower and upper parts, the contribution of the adhesion between tip and sample to the topographical images was eliminated, resulting in better signal-to-noise ratio. DFM of the single stranded RNA genome of a human rhinovirus showed loops protruding from a condensed RNA core, 20-50 nm in height. The mechanical rigidity of the RNA was determined by single molecule pulling experiments. From fitting RNA stretching curves to the Worm-Like-Chain (WLC) model a persistence length of 1.0+/-0.17 nm was obtained.
Kienberger
Ferry
F
Institute for Biophysics, Johannes Kepler University of Linz, Altenbergerstrasse 69, A-4040 Linz, Austria.
Costa
Lilian T
LT
Zhu
Rong
R
Kada
Gerald
G
Reithmayer
Manuela
M
Chtcheglova
Lilia
L
Rankl
Christian
C
Pacheco
Ana B F
AB
Thalhammer
Stefan
S
Pastushenko
Vassili
V
Heckl
Wolfgang M
WM
Blaas
Dieter
D
Hinterdorfer
Peter
P
D006801:Humans; D018625:Microscopy, Atomic Force / Q000379:methods*; D009532:Nickel / Q000737:chemistry; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000032:analysis / Q000737:chemistry*; D012367:RNA, Viral / Q000032:analysis / Q000737:chemistry*; D012229:Rhinovirus / Q000737:chemistry
D012367:RNA, Viral; D009532:Nickel