Single beam optical tweezers setup with backscattered light detection for three-dimensional measurements on DNA and nanopores.
We introduce a versatile and high precision three-dimensional optical tweezers setup with minimal optical interference to measure small forces and manipulate single molecules in the vicinity of a weak reflective surface. Our tweezers system integrates an inverted optical microscope with a single IR-laser beam that is spatially filtered in an appropriate way to allow force measurements in three dimensions with remarkably high precision when operated in backscattered light detection mode. The setup was tested by overstretching a lambda-DNA in x and z directions (perpendicular and along the optical axis), and by manipulating individual lambda-DNA molecules in the vicinity of a nanopore that allowed quantitative single molecule threading experiments with minimal optical interference.
Sischka
Andy
A
Experimental Biophysics and Applied Nanoscience, Faculty of Physics, Bielefeld Institute for Biophysics and NanoScience (BINAS), Bielefeld University, Bielefeld, Germany. andy.sischka@physik.uni-bielefeld.de
Kleimann
Christoph
C
Hachmann
Wiebke
W
Schäfer
Marcus M
MM
Seuffert
Ina
I
Tönsing
Katja
K
Anselmetti
Dario
D
D010582:Bacteriophage lambda / Q000737:chemistry*; D004279:DNA, Viral / Q000737:chemistry*; D007259:Infrared Rays; D007834:Lasers; D016062:Porosity
D004279:DNA, Viral