Localized cell stiffness measurement using axial movement of an optically trapped microparticle.
A simple optical tweezers design is proposed to manipulate particles in the axial direction and estimate particle position with nanometer sensitivity. Balb3T3 cell is probed using two different-sized particles, and the localized cell stiffness is evaluated using Hertz model. A series of experiments are performed to obtain the necessary parameters for the cell stiffness computation: particle displacement, trapping stiffness, force exertion, and cell deformation. The computed cell stiffness measurements are 17 and 40 Pa using 4 μm- and 2 μm-sized particles, respectively. Results suggest that the proposed optical tweezers scheme can measure the stiffness of a particular cell locale using Hertz model, offering insights about how cells respond to outside mechanical stimulus.
Nara Institute of Science and Technology, Graduate School of Information Science, Nara, Japan 630-0192.
Mary-Clare
MC
Dy
Shigehiko
S
Kanaya
Tadao
T
Sugiura
D000818:Animals; D041702:BALB 3T3 Cells; D001696:Biomechanical Phenomena / Q000502:physiology*; D003584:Cytological Techniques / Q000379:methods*; D055119:Elastic Modulus; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D051379:Mice; D008863:Microspheres; D052898:Optical Tweezers; D016012:Poisson Distribution