Measuring Local Viscosities near Plasma Membranes of Living Cells with Photonic Force Microscopy.

ABSTRACT: The molecular processes of particle binding and endocytosis are influenced by the locally changing mobility of the particle nearby the plasma membrane of a living cell. However, it is unclear how the particle's hydrodynamic drag and momentum vary locally and how they are mechanically transferred to the cell. We have measured the thermal fluctuations of a 1 μm-sized polystyrene sphere, which was placed in defined distances to plasma membranes of various cell types by using an optical trap and fast three-dimensional (3D) interferometric particle tracking. From the particle position fluctuations on a 30 μs timescale, we determined the distance-dependent change of the viscous drag in directions perpendicular and parallel to the cell membrane. Measurements on macrophages, adenocarcinoma cells,

SUBMITTER: Junger F 

PROVIDER: S-EPMC4564688 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature