Integrated microfluidic radioassay and imaging platform for small sample analysis

摘要

An immunocapture-based in vitro kinase assay on an integrated polydimethylsiloxane (PDMS) microfluidics platform that can reproducibly measure kinase activity from as few as 3,000 cells is described. For this platform, the standard radiometric 32P-ATP labeled phosphate transfer assay was adopted. Implementation on a microfluidic device required the development of methods for repeated trapping and mixing of solid-phase affinity micro beads. A solid state beta-particle camera imbedded directly below the microfluidic device was used to provide real-time quantitative detection of the signal from this and other microfluidic radio bioassays. The integrated device can measure ABL protein kinase activity from BCR-ABL positive leukemia patient samples, and can measure the small molecule phosphorylation such as phosphorylation of the deoxycytidine analog 18F-FAC by deoxycytidine kinase (dCK) isolated from cell lysates.

主权项

1. An apparatus for performing a microfluidic radioactivity based assay, comprising:
a microfluidic chip with a microchannel system and at least one reaction element adapted to capture radioactively labeled molecules, the reaction element comprising:
a plurality of reaction columns retaining surface functionalized beads fluidly connected to the microchannel system of the microchip; anda circulation chamber fluidic circuit fluidly connected to an entry port and to an exit port of each reaction column; and a solid state radiation detector coupled to the microfluidic chip; wherein radiation emitted from said microfluidic chip is detected; and wherein said functionalized beads can be removed from the reaction column to the circulation chamber through the exit port, mixed and returned to the reaction column through the column entry port.