Microfluidic concentration-enhanced cellular kinase activity assay.

In this paper, we reported a simple, disposable PDMS micro/nanofluidic preconcentration chip for in vitro concentration-enhanced cell kinase assays. Utilizing the preconcentration (electrokinetic trapping) directly from cell lysate (1 mM ATP) samples, we could achieve at least a 25-fold increase in reaction velocity and 65-fold enhancement in sensitivity. In addition, we shorten the assay time down to less than 10 min, with the sample volume requirements of down to approximately 5 cells. This device could be a generic and powerful tool for diagnostics and systems biology studies at the single-cell level, if properly optimized and integrated with the cell culture microdevices.