METHOD AND SYSTEM FOR GENERATING SPATIALLY AND TEMPORALLY CONTROLLABLE CONCENTRATION GRADIENTS

摘要

The ability to rapidly generate concentration gradients of diffusible molecules has important applications in many chemical and biological studies. The present invention is directed to methods and systems for generating spatially and temporally controllable concentration gradients of molecules (i.e. proteins or toxins) in a portable microfluidic device. The formation of the concentration gradients can be initiated by an induced forward flow and further optimized during an induced backward flow. The forward and backward flows can be either passively induced and/or actively pumped. The centimeter-length gradients along the microfluidic channel can be spatially and temporally controlled by the backward flow. The gradient profile was stabilized by stopping the flow. In one example, a stabilized concentration gradient of a cardiac toxin, Alpha-cypermethrin, generated according to the invention was used to test the response of HL-1 cardiac cells in the microfluidic device, which correlated with toxicity data obtained from multi-well plates. The invention can be useful for bio-logical and chemical processes that require rapid generation of concentration gradients in a portable microfluidic device.