Pulling on super paramagnetic beads with micro cantilevers: single molecule mechanical assay application
| Autor: | Romina Muñoz, Francisco Melo, Felipe Aguilar Sandoval, Christian A. M. Wilson |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Magnetic tweezers
Cantilever Biophysics Nanotechnology Bead Paramagnetism Structural Biology Magnetic trap Molecular Biology Quantitative Biology::Biomolecules business.industry Chemistry Cell Biology equipment and supplies Bacteriophage lambda Microspheres Magnetic field Condensed Matter::Soft Condensed Matter Interferometry Magnetic Fields visual_art Temporal resolution DNA Viral visual_art.visual_art_medium Optoelectronics business human activities |
| Zdroj: | Physical Biology. 12:046011 |
| ISSN: | 1478-3975 |
| DOI: | 10.1088/1478-3975/12/4/046011 |
| Popis: | This paper demonstrates that it is possible to trap and release a super paramagnetic micro bead by fixing three super paramagnetic micro beads in a triangular array at the sensitive end of a micro cantilever, and by simply switching on/off an external magnetic field. To provide evidence of this principle we trap a micro bead that is attached to the free end of single DNA molecule and that has been previously fixed at the other end to a glass surface, using the standard sample preparation protocol of magnetic tweezers assays. The switching process is reversible which preserves the integrity of the tethered molecule, and a local force applied over the tethered bead excludes the neighbouring beads from the magnetic trap. We have developed a quadrature phase interferometer which is able to perform under fluid environments to accurately measure small deflections, which permits the exploration of DNA elasticity. Our results agree with measurements from magnetic tweezer assays performed under similar conditions. Furthermore, compared to the magnetic tweezer methodology, the combination of the magnetic trap with a suitable measurement system for cantilever deflection, allows for the exploration of a wide range of forces using a local method that has an improved temporal resolution. |
| Databáze: | OpenAIRE |
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