2008 NSTI Nanotechnology Conference and Trade Show - Nanotech 2008 - 11th Annual

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TechConnect Summit
Clean Technology 2008

High resolution spatio-temporal dosing of subcellular targets

S. Moorjani, R. Nielson, X.A. Chang and J.B. Shear
University of Texas at Austin, US

chemical dosing, cell cultures, laser ablation, microfluidics

Controlled cell-dosing is important for studying processes like chemotaxis and neuritic pathfinding. Although entire culture dishes are commonly dosed with reagents, there is a need for greater spatio-temporal control over these interactions. Towards this goal, we have developed a cell-dosing strategy in which cells are cultured on an ultra-thin polymer membrane that serves as a barrier between two stacked laminar-flow chambers: one containing the cell-culture, the other the reagent. By focusing a pulsed laser beam onto one or more selected membrane positions, micron-diameter pores can be ablated, through which reagent plumes enter and dose the targeted regions. We can also shut off plumes by photocrosslinking a protein plug over the selected pore. In an attempt to increase the spatio-temporal capabilities of this system, we have been working on changing the orientation of the laminar-flow streams on-the-fly. This can be achieved by replacing the simple cell-culture chamber by a more complex asterisk flow cell. In conjunction with computer-activated pinch-valves, the stream orientation can be changed rapidly, which not only allows for greater coverage but also permits very brief reagent exposures. Presently, eight orientations are possible, which can be further increased by opening multiple valves simultaneously. Also, sub-second resolutions can be obtained.

Nanotech 2008 Conference Program Abstract