In their first application of the device, the team measured the activity of the mutated kinase responsible for chronic myelogenous leukemia. This mutation is targeted by the clinically successful kinase inhibitor Gleevec.
"We are not aware of other work demonstrating solid-state integrated radioactive imaging from a microfluidic platform," said co-investigator Arion Chatziioannou, a UCLA professor of molecular and medical pharmacology.
The resulting microfluidic in vitro kinase radioassay improves reaction efficiency, compared with standard assays, and can be processed in much less time. This greater efficiency, coupled with the high sensitivity of the beta camera, reduces the amount of sample cell input by two to three orders of magnitude, compared with conventional and 96-well assays. The assay includes a kinase immunocapture step to increase specificity towards the kinase of interest.
"To get the kinase assay to work in a microfluidic environment, we needed to develop new protocols and reagents for efficiently manipulating solid-support kinase capture beads using microfluidic trap-and-release valves," said co-investigator Hsian-Rong Tseng , a UCLA professor of molecular and medical pharmacology.
"Integration of the solid-state beta camera allows researchers to monitor the assay in real time, which proved useful during our protocol development and testing," said Cong Fang, the leading graduate student on the project. "The integrated microfluidic and imaging platform opens new possibilities and makes miniaturization of many common radioactivity-based bioassays to the microfluidic realm possible."
"With the integration of the compact camera, the microfluidic format assay has the potential to be developed into inexpensive bench-top, stand-alone units," said UCLA postdoctoral fellow Nam Vu, who led the imaging development.
|Contact: Jennifer Marcus|
University of California - Los Angeles