title: High-speed force mapping on living cells with a small cantilever atomic force microscope.
abstract: The imaging speed of the wide-spread force mapping mode for quantitative mechanical measurements on soft samples in liquid with the atomic force microscope (AFM) is limited by the bandwidth of the z-scanner and viscous drag forces on the cantilever. Here, we applied high-speed, large scan-range atomic force microscopy and small cantilevers to increase the speed of force mapping by ≈10-100 times. This allowed resolving dynamic processes on living mouse embryonic fibroblasts. Cytoskeleton reorganization during cell locomotion, growth of individual cytoskeleton fibers, cell blebbing, and the formation of endocytic pits in the cell membrane were observed. Increasing the force curve rate from 2 to 300 Hz increased the measured apparent Young's modulus of the cells by about 10 times, which facilitated force mapping measurements at high speed.
authors.affiliation: Institute of Applied Physics and LISA+, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Braunsmann
authors.affiliation: Institute of Applied Physics and LISA+, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Seifert
authors.affiliation: Institute of Applied Physics and LISA+, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Rheinlaender
authors.affiliation: Institute of Applied Physics and LISA+, University of Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
authors.forename: Tilman E
authors.initials: TE
authors.lastname: Schäffer
mesh_terms: D000538:Aluminum Silicates; D000818:Animals; D001324:Autoantigens; D002462:Cell Membrane / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000378:metabolism; D055119:Elastic Modulus; D004705:Endocytosis / Q000502:physiology; D004867:Equipment Design; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology; D051379:Mice; D018625:Microscopy, Atomic Force / Q000295:instrumentation* / Q000379:methods*; D008854:Microscopy, Electron; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; D014783:Viscosity
chemical_list: D000538:Aluminum Silicates; D001324:Autoantigens; D024101:Mitochondrial Proteins; C527221:NLRP5 protein, human; D009687:Nuclear Proteins; C011934:mica