Better diagnosis of parasitic infections: rapid, simple enrichment of rare cells by using ultrasound
Parasitic infections like malaria and sleeping sickness affect hundreds of millions of people, primarily in the poorest regions of the world. Diagnosis of these diseases is often difficult because the concentration of parasites in the blood can be very low.
British scientists have now developed a simple chip-based method for enriching rare cells in blood samples. As they report in the journal Angewandte Chemie, this allows the detection limit for the parasites that cause malaria and sleeping sickness to be lowered by two to three orders of magnitude.
Existing techniques for the separation and enrichment of parasites in blood samples are difficult to use in isolated regions and developing countries because they usually require complex chemistry for labeling cells, costly instruments, or extensive infrastructure. An inexpensive technique that requires only small amounts of power, works without labeling the cells, and uses just a drop of blood from a fingertip, is needed.
A team headed by Jonathan M. Cooper at the University of Glasgow has now developed such an approach. Their innovative method is based on an acoustically controlled microchip that is used in a battery-driven, hand-held device. The researchers successfully used their technique to enrich malaria-infected blood cells and the parasite that causes sleeping sickness in blood samples.
The chip contains a special electrode that produces ultrasound when a voltage is applied. If a drop of liquid is placed in a specific location on the device, the form of the acoustic field elicits a particular pattern of flow within the drop: a circular rotational motion.
Particles whose density is lower than that of the liquid are carried against gravity with the upward rising current and transported toward the outer edge of the drop, where they accumulate. In contrast, particles with a higher density collect in the center of the droplet, because they cannot be lifted up.
This works for cells too. Red blood cells infected with the malaria parasite are less dense than non-infected cells. If the density of the drop of blood being examined is adjusted by simply adding a small amount of reagent, the acoustic chip allows the infected red blood cells to be concentrated by a factor of one hundred to one thousand at the outer edge of the blood drop.
The non-infected red blood cells remain at the center of the drop. The method is also suitable for concentrating free-swimming parasites in blood. The researchers were able to enrich trypanosomes, the pathogens that cause sleeping sickness, by using their acoustic chip. Simple staining techniques then make it possible to detect the parasites.
In the future, the technique may be adapted to allow other infectious diseases and rare circulating tumor cells to be detected more readily use of this new technology.
About the Author
Professor Jon Cooper is a Fellow of the Royal Academy of Engineering and holds the Wolfson Chair in Bioengineering at the University of Glasgow. His academic interests include the use of micro- and nanotechnologies for the development of medical diagnostics.
Author: Jonathan M. Cooper, University of Glasgow (UK), http://www.gla.ac.uk/schools/engineering/staff/jonathancooper/
Title: Rare-Cell Enrichment by a Rapid, Label-Free, Ultrasonic Isopycnic Technique for Medical Diagnostics
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201310401
Jonathan M. Cooper | Angewandte Chemie International Edition
Perseus translates proteomics data
27.07.2016 | Max-Planck-Institut für Biochemie
Severity of enzyme deficiency central to favism
26.07.2016 | Universität Zürich
Transparent electronics devices are present in today’s thin film displays, solar cells, and touchscreens. The future will bring flexible versions of such devices. Their production requires printable materials that are transparent and remain highly conductive even when deformed. Researchers at INM – Leibniz Institute for New Materials have combined a new self-assembling nano ink with an imprint process to create flexible conductive grids with a resolution below one micrometer.
To print the grids, an ink of gold nanowires is applied to a substrate. A structured stamp is pressed on the substrate and forces the ink into a pattern. “The...
A new Fraunhofer MEVIS method conveys medical interrelationships quickly and intuitively with innovative visualization technology
On the monitor, a brain spins slowly and can be examined from every angle. Suddenly, some sections start glowing, first on the side and then the entire back of...
Researchers at the U.S. Department of Energy's (DOE) Ames Laboratory have discovered an unusual property of purple bronze that may point to new ways to achieve high temperature superconductivity.
While studying purple bronze, a molybdenum oxide, researchers discovered an unconventional charge density wave on its surface.
Munich Physicists have developed a novel electron microscope that can visualize electromagnetic fields oscillating at frequencies of billions of cycles per second.
Temporally varying electromagnetic fields are the driving force behind the whole of electronics. Their polarities can change at mind-bogglingly fast rates, and...
Breakup of continents with two speed: Continents initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. The final speed can be up to 20 times faster than in the first, slow extension phase.phases
Present-day continents were shaped hundreds of millions of years ago as the supercontinent Pangaea broke apart. Derived from Pangaea’s main fragments Gondwana...
15.07.2016 | Event News
15.07.2016 | Event News
11.07.2016 | Event News
27.07.2016 | Earth Sciences
27.07.2016 | Materials Sciences
27.07.2016 | Earth Sciences