Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Novel microfluidic HIV test is quick and cheap

Microfluidic device uses antibodies to 'capture' white blood cells called T cells affected by HIV

UC Davis biomedical engineer Prof. Alexander Revzin has developed a "lab on a chip" device for HIV testing. Revzin's microfluidic device uses antibodies to "capture" white blood cells called T cells that are affected by HIV. In addition to physically binding these cells the test detects the types and levels of inflammatory proteins (cytokines) released by the cells.

Revzin's team collaborated with UCLA electrical engineer Prof. Aydogan Ozcan to integrate an antibody microarray with a lensfree holographic imaging device that takes only seconds to count the number of captured cells and amount of secreted cytokine molecules. The test returns results six to twelve times faster than traditional approaches and tests six parameters simultaneously, based on a small blood sample. The Revzin team published the results of their experiments in the May 2010 issue of Analytical Chemistry.

With further refinements, the test will have wide potential use for multi-parametric blood analysis performed at the point of care in the developing world and resource-poor areas. Its affordability will also make it an attractive option in wealthier areas. Revzin has filed for a patent and is looking for ways to bring his test into clinical use.

"In addition to HIV testing and monitoring, this device will be useful for blood transfusions, where the safety of blood is frequently in question," Revzin says.

The most accurate and effective way to diagnose and monitor HIV infection involves counting two types of T-cells, calculating the ratio between the two types of T-cells, and measuring cytokines. Scientists do this using a method called flow cytometry that requires an expensive machine and several highly trained specialists. Healthcare workers and AIDS activists in the developing world have called for less expensive, more easily performed tests.

"While the point of care field focuses on detection of single parameter (e.g. CD4 counts), we believe that the simplicity of the test need not compromise information content. So, we set out to develop a test that could be simple and inexpensive but would provide several parameters based on a single injection of a small blood volume," explains Revzin.

The HIV test addresses two distinct challenges of blood analysis: 1) capturing the desired cell type from blood, which contains multiple cell types, and 2) connecting the desired blood cell type with secreted cytokines. The test consists of polymer film imprinted with an array of miniature spots. Each spot contains antibodies specific to the two kinds of T-cells (CD4 and CD8) and three types of cytokines printed in the same array. When the blood flowed across the antibody spots, T cells stopped and stuck on the spots.

Each T-cell type was captured next to antibody spots specific for the cytokines they might produce. When antibodies activated the cells, spots adjacent to the cells captured the cytokines they secreted. This connected a specific T-cell subset to its secreted cytokines. The visible color intensity of antibody spots revealed differences in cytokine production by T-cells. Prof. Ozcan's lensfree on-chip imaging allowed the scientists to rapidly image and count T-cell arrays without the use of any lenses or mechanical scanning. Analysis of CD4 and CD8 T-cell numbers, the CD4/CD8 ratio and three secreted cytokines took only seconds.

In the future, Prof. Revzin envisions adding microarrays to the test that can detect proteins from the HIV and hepatitis C viruses.

Lensfree Holographic Imaging of Antibody Microarrays for High-Throughput Detection of Leukocyte Numbers and Function Gulnaz Stybayeva, Onur Mudanyali, Sungkyu Seo, Jaime Silangcruz, Monica Macal, Erlan Ramanculov, Satya Dandekar, Anthony Erlinger, Aydogan Ozcan, and Alexander Revzin Analytical Chemistry, Vol. 82, No. 9, May 1, 2010 3736�.

Holly Ober | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht Advanced analysis of brain structure shape may track progression to Alzheimer's disease
26.10.2016 | Massachusetts General Hospital

nachricht Indian roadside refuse fires produce toxic rainbow
26.10.2016 | Duke University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

The gene of autumn colours

27.10.2016 | Life Sciences

Polymer scaffolds build a better pill to swallow

27.10.2016 | Life Sciences

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>