Measuring nanoscale forces with living probes.

Optical trapping techniques have been used to investigate fundamental biological processes ranging from the identification of the processive mechanisms of kinesin and myosin to understanding the mechanics of DNA. To date, these investigations have relied almost exclusively on the use of isotropic probes based on colloidal microspheres. However, there are many potential advantages in utilizing more complex probe morphologies: use of multiple trapping points enables control of the interaction volume; increasing the distance between the optical trap and the sample minimizes photodamage in sensitive biological materials; and geometric anisotropy introduces the potential for asymmetric surface chemistry and multifunctional probes. Here we demonstrate that living cells of the freshwater diatom Nitzschia subacicularis Hustedt can be exploited as advanced probes for holographic optical tweezing applications. We characterize the optical and material properties associated with the high shape anisotropy of the silica frustule, examine the trapping behavior of the living algal cells, and demonstrate how the diatoms can be calibrated for use as force sensors and as force probes in the presence of rat B-cell hybridoma (11B11) cells.

[1]  G. Jaworski,et al.  Zoospore ultrastructure of Zygorhizidium affluens and Z. planktonicum, two chytrids parasitizing the diatom Asterionella formosa , 1988 .

[2]  S. Chu,et al.  Observation of a single-beam gradient force optical trap for dielectric particles. , 1986, Optics letters.

[3]  Richard Gordon,et al.  The Glass Menagerie: diatoms for novel applications in nanotechnology. , 2009, Trends in biotechnology.

[4]  Graham M. Gibson,et al.  Stereoscopic particle tracking for 3D touch, vision and closed-loop control in optical tweezers , 2011 .

[5]  H J Tiziani,et al.  Optical particle trapping with computer-generated holograms written on a liquid-crystal display. , 1999, Optics letters.

[6]  K. Neuman,et al.  Optical trapping. , 2004, The Review of scientific instruments.

[7]  W. Greenleaf,et al.  High-resolution, single-molecule measurements of biomolecular motion. , 2007, Annual review of biophysics and biomolecular structure.

[8]  Peter J. Pauzauskie,et al.  Optical trapping and integration of semiconductor nanowire assemblies in water , 2006, Nature materials.

[9]  M J Padgett,et al.  Calibration of optically trapped nanotools , 2010, Nanotechnology.

[10]  Johannes Courtial,et al.  Holographic assembly workstation for optical manipulation , 2008 .

[11]  G. Spalding,et al.  Computer-generated holographic optical tweezer arrays , 2000, cond-mat/0008414.

[12]  D B Phillips,et al.  Position clamping of optically trapped microscopic non-spherical probes. , 2011, Optics express.

[13]  Marr,et al.  Optical Trapping of Titania/Silica Core-Shell Colloidal Particles. , 2000, Journal of colloid and interface science.

[14]  S. Smith,et al.  Single-molecule studies of DNA mechanics. , 2000, Current opinion in structural biology.

[15]  K. König,et al.  Cell damage by near-IR microbeams , 1995, Nature.

[16]  D B Phillips,et al.  Download details: IP Address: 137.222.59.47 , 2011 .

[17]  Simon Hanna,et al.  Thermal motion of a holographically trapped SPM-like probe , 2009, Nanotechnology.

[18]  Halina Rubinsztein-Dunlop,et al.  Optically driven micromachine elements , 2001 .

[19]  Peter Bøggild,et al.  Actuation of microfabricated tools using multiple GPC-based counterpropagating-beam traps. , 2005, Optics express.