Microfluidics

Once the content of a useful signature is determined (what genes give us the best information for a particular situation), this signature will need to be implemented in a manner that provides a rapid readout of the predicted dose without the need for highly trained technicians or professional interpretation. Prototypes for potential approaches to this problem have been developed in Project 2, with further development and testing ongoing in a BARDA-funded project.

Development of Hand-Held Sample Preparation Electronics

We started with a simple breadboard system prototype for a portable sample preparation instrument. Since then, we have designed and built a prototype that was able to demonstrate all fluidic functions (pumping and valving) required for sample preparation. The figure shows the assembled printed circuit board holding a microprocessor system and voltage regulator unit that can be programmed by a personal computer via an integrated data port. After programming, the system can run the pre-programmed sequence to activate an array of different pumps and valves to control sample preparation.

Integrated microfluidic systems for biodosimetry

Instrumentation to control the prototype cartridge was designed and fabricated by the Project 2 Team. While this prototype device demonstrated the functionality of controlling an integrated cartridge able to carry out the functions of the qNPA assay, the next stage would be to further miniaturize the device and incorporate issues relating to design for manufacturability (DFM).

Assay intra- and inter-comparisons

Although our early prototypes incorporated quantitative nuclease protection as the assay chemistry, more recent developments focus on the Chemical Ligation-dependent Probe Amplification (CLPA) assay. In a NATO comparison exercise, the CLPA approach provided dose estimates nearly as good as those of the dicentric assay, but in much less time.