Bioengineering Lecture

 Major improvements in human health in the developing world (and significant reductions in the cost of healthcare in the developed world) could be achieved if we could decentralize the testing of pathogens from human samples, and do so at very low cost.  One enabling technology that we have been exploring for 5 years is the use of porous matrices as a replacement for pumps in microfluidics.  Under support of NIH NIAID, our lab leads a team developing a low-cost method for high-sensitivity protein-binding assays for point-of-care detection of infectious disease (initial target: influenza). The team consists of UW, Seattle Children's Hospital, PATH, and GE Global Research. Under support of DARPA DSO, we are developing a multiplexable autonomous disposable nucleic acid amplification test system for the same purpose (initial targets Staphylococcus aureus and influenza). The team is the same, plus Gaetano Borriello, Ferric Fang, and Epoch Biosciences. Both systems are based on novel uses of inexpensive paper and paper-like membranes. Both are designed to be instrument-free fully-disposable diagnostic platforms capable of sensitive detection of multiple pathogens from biological samples. The designs allow sample-to-result testing anywhere, and will be simple enough for untrained users.  Output will be an image capable of being captured (and transmitted for interpretation) by a smart phone, which would be an optional instrument to help analyze test results. 

Both prototypes are designed to detect pathogens from a nasal swab, and share the use of a number of novel paper-fluidic tools. Recent progress on the protein binding assay includes development of de-novo proteins for viral protein capture by the David Baker laboratory, methods for analyzing their association in paper, and their controlled release from the substrates. In the nucleic acid assay, we have demonstrated the detection of a few Staphylococcus aureus bacteria using an isothermal amplification of characteristic bacterial DNA sequences.  The prototype integrates 1) lysis of the nasal swab sample in a tube, 2) isothermal amplification of the DNA obtained, and 3) detection of the amplified target using colored labels on a lateral flow strip.