A force calibration standard for magnetic tweezers.
Rev Sci Instrum
; 85(12): 123114, 2014 Dec.
Article
en En
| MEDLINE
| ID: mdl-25554279
ABSTRACT
To study the behavior of biological macromolecules and enzymatic reactions under force, advances in single-molecule force spectroscopy have proven instrumental. Magnetic tweezers form one of the most powerful of these techniques, due to their overall simplicity, non-invasive character, potential for high throughput measurements, and large force range. Drawbacks of magnetic tweezers, however, are that accurate determination of the applied forces can be challenging for short biomolecules at high forces and very time-consuming for long tethers at low forces below â¼1 piconewton. Here, we address these drawbacks by presenting a calibration standard for magnetic tweezers consisting of measured forces for four magnet configurations. Each such configuration is calibrated for two commonly employed commercially available magnetic microspheres. We calculate forces in both time and spectral domains by analyzing bead fluctuations. The resulting calibration curves, validated through the use of different algorithms that yield close agreement in their determination of the applied forces, span a range from 100 piconewtons down to tens of femtonewtons. These generalized force calibrations will serve as a convenient resource for magnetic tweezers users and diminish variations between different experimental configurations or laboratories.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Biofisica
/
Calibración
/
Campos Magnéticos
/
Imanes
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Rev Sci Instrum
Año:
2014
Tipo del documento:
Article
País de afiliación:
Países Bajos