title: Reliable measurement of elastic modulus of cells by nanoindentation in an atomic force microscope.
abstract: The elastic modulus of an oral cancer cell line UM1 is investigated by nanoindentation in an atomic force microscope with a flat-ended tip. The commonly used Hertzian method gives apparent elastic modulus which increases with the loading rate, indicating strong effects of viscoelasticity. On the contrary, a rate-jump method developed for viscoelastic materials gives elastic modulus values which are independent of the rate-jump magnitude. The results show that the rate-jump method can be used as a standard protocol for measuring elastic stiffness of living cells, since the measured values are intrinsic properties of the cells.
authors.affiliation: Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China.
authors.forename: Z L
authors.initials: ZL
authors.lastname: Zhou
authors.forename: A H W
authors.initials: AH
authors.lastname: Ngan
authors.forename: B
authors.initials: B
authors.lastname: Tang
authors.forename: A X
authors.initials: AX
authors.lastname: Wang
mesh_terms: D045744:Cell Line, Tumor; D055119:Elastic Modulus; D006245:Hardness Tests / Q000379:methods*; D006801:Humans; D018625:Microscopy, Atomic Force; D036103:Nanotechnology / Q000379:methods*; D015203:Reproducibility of Results