title: In situ mechanical interferometry of matrigel films.
abstract: Many biological materials and cell substrates are very soft (Young's modulus <500 Pa) and it is difficult to characterize their mechanical properties. Here we report local elasticity of the surface layers of Matrigel films used for cell culture. We used a new measurement technology, mechanical imaging interferometry, to obtain point mechanical measurements over micron-sized areas. The median values of 650 +/- 400 Pa (# measurements, n = 50), determined by the Hertz contact model, agree well with bulk measurements; however, on the microscale, the films were heterogeneous and contained regions distinctly stiffer than average (1-2 kPa). The first measurement of yield strengths of 170 +/- 100 Pa (n = 43) indicates that Matrigel films deform plastically at stress levels of similar scale to cell tractional forces.
authors.affiliation: Department of Chemistry and Biochemistry, University of California Los Angeles, 607 Charles Young Drive East, Los Angeles, California 90095, USA. jreed@cnsi.ucla.edu
authors.forename: Jason
authors.initials: J
authors.lastname: Reed
authors.forename: Wanda J
authors.initials: WJ
authors.lastname: Walczak
authors.forename: Odessa N
authors.initials: ON
authors.lastname: Petzold
authors.forename: James K
authors.initials: JK
authors.lastname: Gimzewski
mesh_terms: D018929:Cell Culture Techniques; D003094:Collagen; D004338:Drug Combinations; D007797:Laminin; D011509:Proteoglycans
chemical_list: D004338:Drug Combinations; D007797:Laminin; D011509:Proteoglycans; C059485:matrigel; D003094:Collagen