Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/18686
Title: Probing mechanical properties of living cells by atomic force microscopy with blunted pyramidal cantilever tips
Author: Rico Camps, Félix
Roca-Cusachs Soulere, Pere
Gavara, Núria
Farré Ventura, Ramon
Rotger i Estapé, Maria del Mar
Navajas Navarro, Daniel
Keywords: Microscòpia de força atòmica
Biofísica
Cèl·lules
Atomic force microscopy
Biophysics
Cells
Issue Date: 2005
Publisher: The American Physical Society
Abstract: Atomic force microscopy (AFM) allows the acquisition of high-resolution images and the measurement of mechanical properties of living cells under physiological conditions. AFM cantilevers with blunted pyramidal tips are commonly used to obtain images of living cells. Measurement of mechanical properties with these tips requires a contact model that takes into account their blunted geometry. The aim of this work was to develop a contact model of a blunted pyramidal tip and to assess the suitability of pyramidal tips for probing mechanical properties of soft gels and living cells. We developed a contact model of a blunted pyramidal tip indenting an elastic half-space. We measured Young’s modulus ( E ) and the complex shear modulus ( G ∗ = G ′ + i G ′′ ) of agarose gels and A549 alveolar epithelial cells with pyramidal tips and compared them with those obtained with spherical tips. The gels exhibited an elastic behavior with almost coincident loading and unloading force curves and negligible values of G ′′ . E fell sharply with indentation up to ∼ 300 nm , showing a linear regime for deeper indentations. A similar indentation dependence of E with twofold lower values at the linear regime was obtained with the spherical tip fitted with Hertz’s model. The dependence of E on indentation in cells paralleled that found in gels. Cells exhibited viscoelastic behavior with G ′′ / G ′ ∼ 1 / 4 . Pyramidal tips commonly used for AFM imaging are suitable for probing mechanical properties of soft gels and living cells.
Note: Reproducció digital del document publicat a: http://dx.doi.org/10.1103/PhysRevE.72.021914
It is part of: Physical Review E, 2005, vol. 72, núm. 2, p. 021914-1 - 021914-10
Related resource: http://dx.doi.org/10.1103/PhysRevE.72.021914
URI: http://hdl.handle.net/2445/18686
ISSN: 1063-651X
Appears in Collections:Articles publicats en revistes (Ciències Fisiològiques)

Files in This Item:
File Description SizeFormat 
532168.pdf338.16 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.