1063/1.3457121]”
“Recently, interest in single cell analysis has increased because of its potential for improving our understanding of cellular processes. Single cell operation and attachment is indispensable to realize this task. In this paper, we employed a simple and direct method for single-cell attachment and culture in a closed microchannel. The microchannel surface was modified by applying a nonbiofouling polymer, 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer, and a nitrobenzyl photocleavable linker. Using ultraviolet (UV) light irradiation, the MPC polymer was selectively removed by a photochemical reaction that adjusted the cell adherence inside the microchannel. To obtain the

desired single endothelial cell patterning in the microchannel, cell-adhesive regions were controlled by use of round photomasks with diameters of 10, 20, 30, or 50 mu m. Single-cell adherence patterns Vactosertib TGF-beta/Smad inhibitor were formed after 12 h of incubation, only when 20 and 30 mu m photomasks were used, and the proportions of adherent and nonadherent cells among the entire UV-illuminated areas were 21.3%+/- 0.3% and 7.9%+/- 0.3%, respectively. The frequency of single-cell adherence in the case of the 20 mu m photomask was 2.7 times greater than that in the case of the 30 mu m photomask. We found that the 20 mu m photomask was optimal for the formation of single-cell adherence patterns in the microchannel. This technique can be a powerful tool for analyzing environmental factors like

cell-surface and cell-extracellular matrix contact. (C) 2010 American Institute of Physics. [doi:10.1063/1.3494287]“
“A microfluidic device with planar square electrodes is developed for capturing particles from high conductivity selleck chemicals media using negative dielectrophoresis (n-DEP). Specifically, Bacillus subtilis and Clostridium sporogenes spores, and polystyrene particles are tested in NaCl solution (0.05 and 0.225 S/m), apple juice (0.225 S/m), and milk (0.525 S/m). Depending on the conductivity of the medium, the Joule heating produces electrothermal flow (ETF), which continuously circulates and transports the particles to the DEP capture sites. Combination of the ETF and n-DEP results in different particle

capture efficiencies as a function of the conductivity. JNK-IN-8 Utilizing 20 mu m height DEP chambers, “”almost complete”" and rapid particle capture from lower conductivity (0.05 S/m) medium is observed. Using DEP chambers above 150 mu m in height, the onset of a global fluid motion for high conductivity media is observed. This motion enhances particle capture on the electrodes at the center of the DEP chamber. The n-DEP electrodes are designed to have well defined electric field minima, enabling sample concentration at 1000 distinct locations within the chip. The electrode design also facilitates integration of immunoassay and other surface sensors onto the particle capture sites for rapid detection of target micro-organisms in the future. (C) 2010 American Institute of Physics. [doi:10.1063/1.