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
Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute
Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy