ABSTRACT
We fabricated a microfluidic device for the entrapment of nonadherent cells. Solution exchange was easily performed by introducing the solution into the cell-trapping microchannel. Immunostaining and labeling of the cell membrane of THP-1 cells were demonstrated using this device, which does not require cumbersome repetition of centrifugation and resuspension steps.
Subject(s)
Cell Membrane/metabolism , Cell Separation/methods , Microfluidic Analytical Techniques/instrumentation , Actins/metabolism , Cell Adhesion , Cell Line , Cell Separation/instrumentation , Fluorescent Dyes , Humans , Monocytes/cytology , Monocytes/immunology , Monocytes/metabolismABSTRACT
Nanomechanical properties of free-standing reversed surfactant bilayers, dried foam films (DFFs), were examined via AFM by fitting local force-indentation curves with a Hertzian model. The Young's moduli of four kinds of bilayers were in a range of 10-30 MPa.
Subject(s)
Membranes, Artificial , Nanotechnology/methods , Surface-Active Agents/chemistry , Elasticity , Microscopy, Atomic Force , Particle Size , Surface PropertiesABSTRACT
Bacteriorhodopsin (BR), which is rich in alpha-helical structure, was spread onto water with single-wall carbon nanotubes (SCNTs). After a Langmuir trough was used to apply compressive surface pressure to maintain the alpha-helices monolayer of denatured BR, the composite films comprising alpha-helices and SCNTs were transferred horizontally onto substrates. Atomic force microscopy (AFM) and fluorescence microscopy observation suggested that alpha-helices in contact with SCNTs changed into beta-sheets. High-resolution transmission electron microscopy (HR-TEM) showed 0.54 nm periodicity characteristic of the turn of alpha-helical structure in the SCNTs-free alpha-helix monolayer region and showed the 0.70 nm periodicity of beta-sheet pleated structure in the region where SCNTs were covered with unfolded BR. Unique features of carbon nanotubes that trigger conformational changes of a protein were revealed.
