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A Microflow Cytometer On A Chip, Joel P. Golden, Jason Kim, George P. Anderson, Nicole N. Hashemi, Peter J. Howell, Frances S. Ligler
A Microflow Cytometer On A Chip, Joel P. Golden, Jason Kim, George P. Anderson, Nicole N. Hashemi, Peter J. Howell, Frances S. Ligler
Nastaran Hashemi
A rapid, automated, multi-analyte Microflow Cytometer is being developed as a portable, field-deployable sensor for onsite diagnosis of biothreat agent exposure and environmental monitoring. The technology relies on a unique method for ensheathing a sample stream in continuous flow past an interrogation region where optical fibers provide excitation and collect emission. This approach efficiently focuses particles in the interrogation region of the fluidic channel, avoids clogging and provides for subsequent separation of the core and sheath fluids in order to capture the target for confirmatory assays and recycling of the sheath fluid. Fluorescently coded microspheres provide the capability for highly …
Dynamic Reversibility Of Hydrodynamic Focusing For Recycling Sheath Fluid, Nicole N. Hashemi, Peter B. Howell Jr., Jeffrey S. Erickson, Joel P. Golden, Francis S. Ligler
Dynamic Reversibility Of Hydrodynamic Focusing For Recycling Sheath Fluid, Nicole N. Hashemi, Peter B. Howell Jr., Jeffrey S. Erickson, Joel P. Golden, Francis S. Ligler
Nastaran Hashemi
The phenomenon of "unmixing" has been demonstrated in microfluidic mixers, but here we manipulate laminar flow streams back to their original positions in order to extend the operational utility of an analytical device where no mixing is desired. Using grooves in the channel wall, we passively focus a sample stream with two sheath streams to center it in a microchannel for optical analysis. Even though the sample stream is completely surrounded by sheath fluid, reversing the orientation of the grooves in the channel walls returns the sample stream to its original position with respect to the sheath streams. We demonstrate …