Spatial and temporal application of microfluidics to cells

The rapid solution exchange around the adhesive single cell has recently received a great deal of attention from the viewpoint cell response analyses. We recently constructed a new system, which enables the replacement of solutions rapidly and precisely, by utilizing laminar flow technology. The sharp boundary of the adjoining two liquids (no mixing) moves around the cells, and minimum increments of the boundary shift are controlled at an interval of roughly 1.6 mum, and the time required for this movement is 20 msec. The system can be used for the analysis of intracellular Ca²⁺ concentrations using a fluorescent indicator, in which the cells are thus stimulated by the rapid exchange of the solution. These results suggest that the spatial and temporal control of the solution around the adhesive single cell can thus be realized