The Optical Stretcher: A Novel Laser Tool to Micromanipulate Cells

Center for Nonlinear Dynamics, Department of Physics, University of Texas at Austin, Texas 78712, USA.
Biophysical Journal (Impact Factor: 3.97). 09/2001; 81(2):767-84. DOI: 10.1016/S0006-3495(01)75740-2
Source: PubMed


When a dielectric object is placed between two opposed, nonfocused laser beams, the total force acting on the object is zero but the surface forces are additive, thus leading to a stretching of the object along the axis of the beams. Using this principle, we have constructed a device, called an optical stretcher, that can be used to measure the viscoelastic properties of dielectric materials, including biologic materials such as cells, with the sensitivity necessary to distinguish even between different individual cytoskeletal phenotypes. We have successfully used the optical stretcher to deform human erythrocytes and mouse fibroblasts. In the optical stretcher, no focusing is required, thus radiation damage is minimized and the surface forces are not limited by the light power. The magnitude of the deforming forces in the optical stretcher thus bridges the gap between optical tweezers and atomic force microscopy for the study of biologic materials.

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    • "Briefly, cells were held in between two counter propagating laser beams (λ = 1064 nm). Due to applied laser power, cells experienced both an optical force pulling on the cell membrane (σ ≈ 10Pa peak stress [16]) and an increase in temperature caused by laser light absorption ( "
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    New Journal of Physics 07/2015; 17(7). DOI:10.1088/1367-2630/17/7/073010 · 3.56 Impact Factor
    • "During the last few years, different fabrication techniques have been developed (Guck et al. 2001; Lincoln et al. 2007; Bellini et al. 2010), and optical stretchers have been applied to explore the deformability of oral cancer cells (Remmerbach et al. 2009), of Abstract Acoustophoresis is a widely reported and used technique for microparticle manipulation and separation. "
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    ABSTRACT: Acoustophoresis is a widely reported and used technique for microparticle manipulation and separation. In the study described here, acustophoresis is employed to prefocus the flow (i.e., focusing occurring upstream of the analysis region) in a microfluidic chip intended for optical trapping and stretching. The whole microchip is made of silica with optical waveguides integrated by femtosecond laser writing. The acoustic force is produced by driving an external piezoelectric ceramic attached underneath the microchip at the chip resonance frequency. Thanks to an efficient excitation of acoustic waves in both water and glass, acoustophoretic focusing is observed along the channel length (>40 mm) and it is successfully demonstrated both with polystyrene beads, swollen red blood cell, and cells from mouse fibroblast cellular lines (L929). Moreover, by comparing results of cell stretching measurements, we demonstrate that acoustic waves do not alter the optical deformability of the cells and that the acoustic prefocusing results in a considerable enhancement of throughput in optical stretching experiments.
    Microfluidics and Nanofluidics 06/2015; 19(4):837-844. DOI:10.1007/s10404-015-1609-x · 2.53 Impact Factor
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    • "Single suspended cells are transported through a square glass capillary placed perpendicularly to the optical fibers. Two counter-propagating 'stretch laser fibers' (yellow) form the classical optical stretcher trap, where the cells can be held and stretched by optical forces [43]. In our setup, the temperature of the trapped cells can be changed quickly by laser light emission of the additional 'heat laser fibers' (red). "
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    New Journal of Physics 07/2014; 16(7):073009. DOI:10.1088/1367-2630/16/7/073009 · 3.56 Impact Factor
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