Lab-on-a-chip Devices for Cell Separation and Identification A PhD project at Macquarie University under the guidance of Dr. David Inglis and Prof. Ewa Goldys. Feb 2008

Microbes, cells and small organisms come in a wide array of shapes and sizes Yeast Blood Cells cryptosporidium Photo Credit: H.D.A Lindquist, U.S. EPA

Microfluidic or Lab-on-a-chip Devices can be used to separate different cell types Various blood cell separations have been demonstrated: J. A. Davis, D. W. Inglis, K. M. Morton, D. A. Lawrence, L. R. Huang, S. Y. Chou, J. C. Sturm, and R. H. Austin, Deterministic hydrodynamics: taking blood apart, Proc. Nat. Acad. Sci. (USA), vol. 103, pp , D. W. Inglis, J. A. Davis, T. J. Zieziulewicz, D. A. Lawrence, R. H. Austin, and J. C. Sturm, Determining blood cell size using microfluidic hydrodynamics, J. Immunol. Meth., vol. 329, pp , D. W. Inglis, K. J. Morton, J. A. Davis, T. J. Zieziulewicz, D. A. Lawrence, R. H. Austin, and J. C. Sturm, Microfluidic device for label-free measurement of platelet activation, Submitted to Lab on a Chip, Jan 08. But no work yet with microorganisms!

This project will lead to publications which demonstrate the separation of microorganisms on portable inexpensive polymer microfluidic devices. Such devices may have applications in early detection of human diseases such as sepsis and various parasitic diseases as well as management of swimming pool and drinking water quality.

What is Micro-Fluidics Microfluidics –microfabricated structures for fluid handling Engineers know how to microfabricate and build integrated systems  TAS – Micro Total Analysis System –Integrate microfluidic components into a useful device, a “Lab on a Chip” “development and application of micro- and nanofabricated devices and systems for chemical and biochemical measurements. The technology encompasses extensive areas of application in clinical diagnostics, genomics and proteomics, environmental assays, separation science, cellular analysis or drug discovery.” From Micralyne.com Interdisciplinary – Physics, Chemistry, Biology Photolithography Reactive Ion Etching Drill access holes Seal with cover slip Fabrication Process: Fluid goes in

1.4  m 1.5  m 1.6  m 1.7  m 1.8  m 1.9  m 2.0  m 2.1  m 2.2  m 200  m 1 mm Peak width ~10 nm No known method fractionates with such resolution. High Resolution Separation with Size - Position Correlation Can include chirp to fractionate over a range of sizes by varying g or  Huang et al, Science 2004

Cell Separation by Size

~ White blood cells come in different sizes and can be differentiated Healthy Lymphocytes Healthy Lymphocytes Cancerous Lymphocytes Cancerous Lymphocytes

Human platelets change size in response to chemical and temperature stimulus

Proposed Device Use the technique described above to create a simple to use high throughput cell concentrator. Parallel channels for separation and concentration on a glass slide. A second layer distributes fluid to the channels and collects their output. Structures will be molded PDMS. Master mold will be lithographically defined SU-8 polymer. 20-micron PDMS pillars