Dultsev Fedor N, Kolosovsky Eugeny A, Mik Ivan A, Lomzov Alexander A, Pyshnyi Dmitrii V
Institute of Semiconductor Physics, ‡Institute of Chemical Biology and Fundamental Medicine, SB RAS , Novosibirsk, 630090 Russia.
Langmuir. 2014 Apr 8;30(13):3795-801. doi: 10.1021/la402971a. Epub 2014 Mar 26.
After fixing the DNA molecule in the form of a double helix on the surface of a thickness shear mode resonator (QCM), mechanical oscillations at increasing amplitude cause detorsion of the helix. The force necessary for detorsion can be determined from the voltage applied to the QCM at the rupture moment. The high sensitivity of this method is due to the fact that measurements are carried out in the frequency region around the QCM resonance, where any (even very weak) distortions of the consistent oscillating system cause noticeable distortions of the amplitude-frequency dependence, and these distortions are used to fix the rupture moment. The measured rupture forces were within 30-40 pN, and the sensitivity was 10(8) molecules. It was demonstrated that the proposed procedure allows one to determine the factors that affect the stability of the DNA double helix. This procedure can be the basis for the development of a new method of rapid DNA analysis. Experiments performed with model DNA showed that it is possible to reveal complementarity between two DNA samples.
