Bioengineering Department, Box 352255, University of Washington, Seattle, WA 98195, USA
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Bioengineering Department, Box 352255, University of Washington, Seattle, WA 98195, USA |
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Note that the following projects were funded as of the date on
which this page was updated (see last line of page). This does not guarantee
that any of them is funded and active as of the date you read this page,
or that if it is still funded, there are extra funds to support you. If you
are
interested in working on one of these projects, please contact PY's assistant
(see Yager's home page).
| Current Project Title | Funding Source | Dates
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| Development of Microfluidic Diffusion Immunoassay (DIA) | NIH NIBIB |
5/01 – 4/06 |
| Rapid Parallel Salivary Immunoassays on a Disposable | NIH NIDCR |
9/02 – 8/06 |
| Point-of-Care Bioassay System (PCBS) | Singapore-University of Washington Alliance (A*STAR of Singapore) | 5/02 – 4/07 |
| Microfluidic Technology for Gene Delivery Systems | Subcontract from NIBIB grant on which Kenneth Longmuir of UC Irvine is PI | 9/03-8/08 |
| A Multiplex, Point-of-Care Test for Enteric Pathogens | Subcontract from NIAID grant on which Bernhard Weigl of PATH is PI | 9/04 – 8/08 |
| Development of a DNA-Based Detector Array for Microbial Monitoring of the ISS Water System | Subcontract from David Stahl's NASA grant | 1/05 – 12/07 |
| A Point-of-Care Diagnostic System for the Developing World | The Bill and Melinda Gates Foundation, Grand Challenges in Global Health 14 |
7/05 – 6/10 |
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One of the most powerful and versatile biomedical diagnostic tools,
the immunoassay, is used to monitor the levels of drugs and hormones
in body fluids, to diagnose infectious and autoimmune diseases, and
to both diagnose and monitor treatment of cancer. The performance
of immunoassays is today largely restricted to centralized laboratories
because of the need for long assay times, complex and expensive equipment,
and highly trained technicians. If a wider range of the 700 million
immunoassays performed annually in the US alone could be run more
inexpensively, more frequently, and at the point of care, the health
of millions of patients could be improved. Recent developments in
microfluidics suggest that instruments could soon be developed that
would allow immunoassays to be performed as easily as is blood glucose
testing today. |
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The collection of saliva is far preferable to collection of blood from the point of view of the person being sampled. However, in recent years microfluidic technologies for measuring analytes in blood have advanced rapidly, while the use of saliva as an analyte has lagged, both in terms of the number of analytes measured and the environments in which such measurements are made. In part, this is because saliva is more variable than plasma, has analytes in lower concentrations, and contains viscous and adhesive mucins. If it were practical to use saliva for many analytes commonly measured in blood, and to make those measurements on several analytes at once, inexpensively, and in a way not requiring technical training, enormous improvements in the quality, frequency and scope of biomedical testing for research, therapy, and health maintenance would be possible, particularly for ambulatory outpatients. This project will develop an integrated microfluidic system for rapidly, inexpensively, and simultaneously measuring multiple analytes in saliva, and in a simple disposable polymeric laminate format. A microfluidic device to allow rapid extraction of analytes from the mucins in saliva will be developed. Two new but demonstrated immunoassay technologies will be coupled to a microfluidic system that allows dry storage of all reagents at ambient conditions and measures multiple analytes in parallel. These assays can measure low levels of hormones, drugs, metabolites, and even proteins that indicate the presence of disease, as well as compounds specific to the oral cavity such as pathogens and markers for oral cancer. The immunoassays will initially be validated on hormones for which commercial immunoassays are available. Ongoing work on development of parallel diffusion immunoassays will be extended to saliva testing through coupling with the mucin-extraction system. To measure analytes present at concentrations below the limit of detection of the diffusion immunoassay, chemically amplified surface plasmon resonance (SPR) imaging will be used. The design of a novel SPR microscope being developed in this project is shown at left. Dissolution of dry reagent will be employed to decorate the gold surface with multiple capture molecules. Finally, a versatile combined system will be designed and tested that will allow monitoring of samples by the two methods simultaneously. |
More Information on the NIDCR program funding this work
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This project is supported by the Singapore government's A*STAR, through the Singapore University of Washington Alliance (SUWA). We are in active collaboration with Prof. Tjin at Nanyang Technological University, whose work is focused on development of compatible instrumentation. |
The goal of this project is to develop an inexpensive portable assay system for monitoring multiple biochemicals in blood simultaneously and in a few minute at the point of care. The system will be based on a simple microfluidic disposable component containing all chemicals required for the bioassays that can be stored indefinitely at ambient conditions. Work will include development of: appropriate assay chemistry that can be stored dry, disposable laminates that can support several assays types and the storage requirements, a process for reconstituting the assay chemistries after long-term storage (shown schematically on the left), and the low-cost portable instrumentation to read and interpret the assay results. UW is focusing is on the dry reagent technology, microfluidic laminates and fluorescence imaging of enzymatic assays in solution and surface-bound fluorescence immunoassays. |
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The Longmuir laboratory at UC Irvine has developed a non-viral gene delivery system strategy based upon zwitterionic lipid, peptides, and polymer components. Each component can be individually optimized to overcome the sequential barriers to gene delivery, which are 1) assembly, 2) extracellular stabilization, 3) endosomal/lysosomal escape, and 4) nuclear entry in the absence of cell division. The system is assembled in 25% ethanol/75% water mixtures, avoiding the use of toxic organic solvents and detergents. Under subcontract to UC Irvine as part of a a 5-year NIH grant, the Yager group will establish microfluidic technology that could lead to fully automated assembly of non-viral gene delivery complexes (as shown schematically at left). The steps to be explored are:
This work will lead up to integration of the above functions into a single monolithic microfluidic device in a stand-alone workstation, to allow for fully automated, highly reproducible, uniform, point-of-use assembly of the gene delivery complexes. |
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Diarrhea is one of the major causes of death in the developing world, particularly among children. Even in the developed world, the standard method for determining the cause of diarrhea is culturing for bacteria, which can take up to 3 days. A rapid test for the pathogen responsible for particular patients. The Seattle-based nonprofit organization PATH (Program for Appropriate Technologies for Health) has obtained a grant from NIAID to develop a system for measuring the levels of pathogens in human stool samples for the rapid diagnosis of the causes of diarrhea. Subcontractors under the leadership of PATH's Bernhard Weigl are Micronics of Redmond, WA, Dr. Philip Tarr of Washington University in St. Louis, and the Yager group. The final instrument will utilize rapid on-card PCR for the identifying the pathogenic strain. The Yager group is responsible for developing a system for drying, preserving, and rehydrating the reagents required. Shown at left is a preliminary phase diagram for the fluorescence emission of a dye used to monitor the degree of dryness in small samples of the stabilizing matrix. |
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The Yager group is part of a collaboration that includes the Jet Propulsion Laboratory in California that is led by Prof. David Stahl of the UW Department of Civil Engineering and funded by NASA. The aim of the project is to develop a nucleic acid probe microarray-based sensor for the detection and evaluation of microorganisms that contaminate the International Space Station drinking water system. Using this sensor we will not only monitor the microbial contamination, but will identify and quantify the problematic microbial species (e.g., opportunistic pathogens) in the ISS drinking water that pose a health risk to astronauts. The approach is to measure the RNA content of lysed microbes using fluorescence monitoring of a gel-based microarray. The Yager group contribution to the project us converting the current sample preconditioning and processing steps to a microfluidic format. The requirement for low instrument weight and operation in the absence of gravity adds some interesting challenges. Image courtesy of NASA. |
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A Seattle-based consortium led by the Yager group has been awarded $15.4 million by the Bill & Melinda Gates Foundation Grand Challenges in Global Health initiative. The aim of the project is to develop a portable device that promises to bring the technological power of a modern medical diagnostics laboratory to the developing world. The consortium co-investigators are Patrick Stayton of the University of Washington Department of Bioengineering, Bernhard Weigl of PATH, Fred Battrell of Micronics, Inc., WA, and Walt Mahoney of Nanogen, Inc. |
The Grand Challenges in Global Health initiative is a major international effort to achieve scientific breakthroughs against diseases that kill millions of people each year in the world's poorest countries. |
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