Auto- and cross-power spectral analysis of dual trap optical tweezer experiments using Bayesian inference

Review of Scientific Instruments - Tập 83 Số 9 - 2012
Yann von Hansen1,2, Alexander Mehlich2, Benjamin Pelz2, Matthias Rief2, Roland R. Netz1,2
1Freie Universität Berlin 1 Department of Physics, , 14195 Berlin, Germany
2Technische Universität München 2 Physics Department, , 85748 Garching, Germany

Tóm tắt

The thermal fluctuations of micron-sized beads in dual trap optical tweezer experiments contain complete dynamic information about the viscoelastic properties of the embedding medium and—if present—macromolecular constructs connecting the two beads. To quantitatively interpret the spectral properties of the measured signals, a detailed understanding of the instrumental characteristics is required. To this end, we present a theoretical description of the signal processing in a typical dual trap optical tweezer experiment accounting for polarization crosstalk and instrumental noise and discuss the effect of finite statistics. To infer the unknown parameters from experimental data, a maximum likelihood method based on the statistical properties of the stochastic signals is derived. In a first step, the method can be used for calibration purposes: We propose a scheme involving three consecutive measurements (both traps empty, first one occupied and second empty, and vice versa), by which all instrumental and physical parameters of the setup are determined. We test our approach for a simple model system, namely a pair of unconnected, but hydrodynamically interacting spheres. The comparison to theoretical predictions based on instantaneous as well as retarded hydrodynamics emphasizes the importance of hydrodynamic retardation effects due to vorticity diffusion in the fluid. For more complex experimental scenarios, where macromolecular constructs are tethered between the two beads, the same maximum likelihood method in conjunction with dynamic deconvolution theory will in a second step allow one to determine the viscoelastic properties of the tethered element connecting the two beads.

Từ khóa


Tài liệu tham khảo

2008, Annu. Rev. Biochem., 77, 205, 10.1146/annurev.biochem.77.043007.090225

2006, Proc. Natl. Acad. Sci. U.S.A., 103, 12724, 10.1073/pnas.0602995103

2006, Science, 314, 1001, 10.1126/science.1133601

2010, Proc. Natl. Acad. Sci. U.S.A., 107, 2013, 10.1073/pnas.0909854107

2011, Science, 334, 512, 10.1126/science.1207598

2011, Nature (London), 478, 85, 10.1038/nature10498

2011, Phys. Rev. Lett., 107, 228301, 10.1103/PhysRevLett.107.228301

1997, Phys. Rev. Lett., 79, 3286, 10.1103/PhysRevLett.79.3286

2000, Phys. Rev. Lett., 85, 888, 10.1103/PhysRevLett.85.888

2003, Faraday Discuss., 123, 323, 10.1039/b204696b

2006, Proc. Natl. Acad. Sci. U.S.A., 103, 9006, 10.1073/pnas.0603342103

2010, Proc. Natl. Acad. Sci. U.S.A., 107, 21493, 10.1073/pnas.1010476107

1976, Fourier Analysis of Time Series: An Introduction

2004, Rev. Sci. Instrum., 75, 594, 10.1063/1.1645654

2004, Comput. Phys. Commun., 159, 225, 10.1016/j.cpc.2004.02.012

2006, Rev. Sci. Instrum., 77, 063106, 10.1063/1.2204589

2006, Rev. Sci. Instrum., 77, 103101, 10.1063/1.2356852

2010, Rev. Sci. Instrum., 81, 075103, 10.1063/1.3455217

2005, Phys. Rev. Lett., 95, 208302, 10.1103/PhysRevLett.95.208302

2005, Phys. Rev. Lett., 95, 208303, 10.1103/PhysRevLett.95.208303

2008, Phys. Rev. E, 77, 061508, 10.1103/PhysRevE.77.061508

1997, Appl. Opt., 36, 2107, 10.1364/AO.36.002107

2008, Rev. Sci. Instrum., 79, 083103, 10.1063/1.2957652

2008, Rev. Sci. Instrum., 79, 043103, 10.1063/1.2898407

2005, Rev. Sci. Instrum., 76, 025106, 10.1063/1.1851472

1980, Statistical Physics, Part 1, 3rd ed.

1999, Phys. Rev. Lett., 82, 2211, 10.1103/PhysRevLett.82.2211

2001, Philos. Trans. R. Soc. London, Ser. A, 359, 883, 10.1098/rsta.2000.0805

2001, Phys. Rev. E, 64, 061403, 10.1103/PhysRevE.64.061403

2000, Phys. Rev. Lett., 84, 5014, 10.1103/PhysRevLett.84.5014

Selvin, 2008, High-resolution dual-trap optical tweezers with differential detection, Single-Molecule Techniques: A Laboratory Manual

2004, Rev. Sci. Instrum., 75, 2787, 10.1063/1.1785844

1851, Proc. Cambridge Philos. Soc., 9, 8

1989, Phys. Rev. Lett., 63, 1747, 10.1103/PhysRevLett.63.1747

1992, Phys. Rev. A, 46, 1942, 10.1103/PhysRevA.46.1942

2010, Eur. Phys. J. E, 32, 147, 10.1140/epje/i2010-10610-7

1983, Physica A, 120, 77, 10.1016/0378-4371(83)90268-6

1969, J. Chem. Phys., 50, 4831, 10.1063/1.1670977

1978, J. Chem. Phys., 69, 1352, 10.1063/1.436761

1927, Neuere Methoden und Ergebnisse in der Hydrodynamik

1991, Microhydrodynamics - Principles and Selected Applications

1956, J. Chem. Phys., 24, 269, 10.1063/1.1742462

2004, Phys. Rev. E, 69, 031407, 10.1103/PhysRevE.69.031407

2006, Phys. Rev. Lett., 97, 248301, 10.1103/PhysRevLett.97.248301

2003, Rev. Sci. Instrum., 74, 3246, 10.1063/1.1584085

1982, Astrophys. J., 263, 835, 10.1086/160554

1986, Astrophys. J., 302, 757, 10.1086/164037

levmar: Levenberg-marquardt nonlinear least squares algorithms in c/c++

See the Supplementary material at http://dx.doi.org/10.1063/1.4753917 for the explanation of the observed crosstalk asymmetry.

2003, J. Appl. Phys., 93, 3167, 10.1063/1.1554755

1989, Theory of Discrete and Continuous Fourier Analysis

1992, Numerical Recipes in C, 2nd ed.