Corporate Banner
Satellite Banner
Proteomics
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Oscillating Microscopic Beads Could be Key to Biolab on a Chip

Published: Tuesday, September 25, 2012
Last Updated: Tuesday, September 25, 2012
Bookmark and Share
MIT team finds way to manipulate and measure magnetic particles without contact, potentially enabling multiple medical tests on a tiny device.

If you throw a ball underwater, you’ll find that the smaller it is, the faster it moves: A larger cross-section greatly increases the water’s resistance. Now, a team of MIT researchers has figured out a way to use this basic principle, on a microscopic scale, to carry out biomedical tests that could eventually lead to fast, compact and versatile medical-testing devices.

The results, based on work by graduate student Elizabeth Rapoport and assistant professor Geoffrey Beach, of MIT’s Department of Materials Science and Engineering (DMSE), are described in a paper published in the journal Lab on a Chip. MIT graduate student Daniel Montana ’11 also contributed to the research as an undergraduate.

The balls used here are microscopic magnetic beads that can be “decorated” with biomolecules such as antibodies that cause them to bind to specific proteins or cells; such beads are widely used in biomedical research. The key to this new work was finding a way to capture individual beads and set them oscillating by applying a variable magnetic field. The rate of their oscillation can then be measured to assess the size of the beads.

When these beads are placed in a biological sample, biomolecules attach to their surfaces, making the beads larger — a change that can then be detected through the biomolecules effect on the beads’ oscillation. This would provide a way to detect exactly how much of a target biomolecule is present in a sample, and provide a way to give a virtually instantaneous electronic readout of that information.

This new technique, for the first time, allows these beads — each about one micrometer, or millionth of a meter, in diameter — to be used for precise measurements of tiny quantities of materials. This could, for example, lead to tests for disease agents that would need just a tiny droplet of blood and could deliver results instantly, instead of requiring laboratory analysis.

In a paper published earlier this year in the journal Applied Physics Letters, the same MIT researchers described their development of a technique for creating magnetic tracks on a microchip surface, and rapidly transporting beads along those tracks. (The technology required is similar to that used to read and write magnetic data on a computer’s hard disk.) An operational device using this new approach would consist of a small reservoir above the tracks, where the liquid containing the magnetic beads and the biological sample would be placed.

Rather than pumping the fluid and the particles through channels, as in today’s microfluidic devices, the particles would be controlled entirely through changes in applied magnetic fields. By controlling the directions of magnetic fields in closely spaced adjacent regions, the researchers create tiny areas with extremely strong magnetic fields, called magnetic domain walls, whose position can be shifted along the track. “We can use the magnetic domain walls to capture and transport the beads along the tracks,” Beach says.

In the researchers’ most recent paper, Rapoport explains, they have now shown that once a bead is captured, a magnetic field can be used to shake it back and forth. Then, the researchers measure how fast the bead moves as they change the frequency of the oscillation. “The resonant frequency is a function of the bead size,” she says — and could be used to reveal whether the bead has grown in size through attachment to a target biomolecule.

Besides being potentially quicker and requiring a far smaller biological sample to produce a result, such a device would be more flexible than existing chip-based biomedical tests, the researchers say. While most such devices are specifically designed to detect one particular kind of protein or disease agent, this new device could be used for a wide variety of different tests, simply by inserting a fresh batch of fluid containing beads coated with the appropriate reactant. After the test, the material could be flushed out, and the same chip used for a completely different test by inserting a different type of magnetic beads. “You’d just use it, wash it off, and use it again,” Rapoport says.

There are dozens of types of magnetic beads commercially available now, which can be coated to react with many different biological materials, Beach explains, so such a test device could have enormous flexibility.

The MIT team has not yet used the system to detect biological molecules. Rather, they used magnetic beads of different sizes to demonstrate that their system is capable of detecting size differences corresponding to those between particles that are bound to biological molecules and those that are not. Having succeeded in this proof of concept, the researchers’ next step will be to repeat the experiment using biological samples.

“We now have all the elements required to make a sensing device,” Beach says. The next step is to combine the pieces in an operational device and demonstrate its performance.

R. Sooryakumar, a professor of physics at Ohio State University who was not involved in this research, calls this an “innovative approach.”

“It is very interesting how the researchers combine technologies that are well understood for applications in computing and data storage, and apply them to something completely different,” Sooryakumar says. He adds, “These magnetic devices are potentially valuable tools that could go well beyond how one may normally expect them to be used. The ramifications, for example in food safety and health care, such as pathogen or cancer detection, are indeed exciting.”


Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,400+ scientific posters on ePosters
  • More than 3,700+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Bacterial Computing
The “friendly” bacteria inside our digestive systems are being given an upgrade, which may one day allow them to be programmed to detect and ultimately treat diseases such as colon cancer and immune disorders.
Monday, July 13, 2015
New Approach to Global Health Challenges
MIT’s Institute for Medical Engineering and Science brings many tools to the quest for new disease treatments and diagnostic devices.
Friday, September 27, 2013
Why Tumors Become Drug-Resistant
New findings could lead to drugs that fight back when tumors don’t respond to treatment.
Monday, August 12, 2013
Reducing Caloric Intake Delays Nerve Cell Loss
Study points to role of protein in anti-aging benefits of calorie restriction.
Thursday, May 23, 2013
Study IDs Key Protein for Cell Death
Findings may offer a new way to kill cancer cells by forcing them into an alternative programmed-death pathway.
Tuesday, May 14, 2013
Device Finds Stray Cancer Cells in Patients’ Blood
A microfluidic device that captures circulating tumor cells could give doctors a noninvasive way to diagnose and track cancers.
Wednesday, April 10, 2013
Sorting out the Structure of a Parkinson’s Protein
Computer modeling may resolve conflicting results and offer hints for new drug-design strategies.
Tuesday, April 02, 2013
New Technology May Enable Earlier Cancer Diagnosis
Nanoparticles amplify tumor signals, making them much easier to detect in the urine.
Friday, December 21, 2012
Evolution: It’s All in How You Splice It
MIT biologists find that alternative splicing of RNA rewires signaling in different tissues and may often contribute to species differences.
Friday, December 21, 2012
Researchers Synthesize a New Kind of Silk Fiber
Scientists find that music can help fine-tune the material’s properties.
Thursday, November 29, 2012
New Injectable Gels Toughen up after Entering the Body
These more durable gels could find applications in drug delivery and tissue engineering.
Friday, November 16, 2012
A Step Toward Stronger Polymers
Counting loops that weaken materials could help researchers eliminate structural flaws.
Tuesday, November 06, 2012
A New Glow for Electron Microscopy
Protein-labeling technique allows high-resolution visualization of molecules inside cells.
Monday, October 22, 2012
Strategies Converge on Target in Rare Leukemia
In order to treat AMKL in patients who do not respond to current therapies, researchers need a protein target at which to take aim.
Wednesday, August 08, 2012
Researchers Build a Toolbox for Synthetic Biology
Engineers design new proteins that can help control novel genetic circuits in cells.
Friday, August 03, 2012
Scientific News
TOPLESS Plants Provide Clues to Human Molecular Interactions
Scientists at Van Andel Research Institute have revealed an important molecular mechanism in plants that has significant similarities to certain signaling mechanisms in humans, which are closely linked to early embryonic development and to diseases such as cancer.
Toxin from Salmonid Fish has Potential to Treat Cancer
Researchers from the University of Freiburg decode molecular mechanism of fish pathogen.
Study Finds Non-Genetic Cancer Mechanism
Cancer can be caused solely by protein imbalances within cells, a study of ovarian cancer has found.
Long-sought Discovery Fills in Missing Details of Cell 'Switchboard'
A biomedical breakthrough reveals never-before-seen details of the human body’s cellular switchboard that regulates sensory and hormonal responses.
Rice Disease-Resistance Discovery Closes the Loop for Scientific Integrity
Researchers reveal how disease resistant rice detects and responds to bacterial infections.
The Mystery of the Instant Noodle Chromosomes
Researchers from the Lomonosov Moscow State University evaluated the benefits of placing the DNA on the principle of spaghetti.
New Mussel-Inspired Surgical Protein Glue
Korean scientists have developed a light-activated, mussel protein-based bioadhesive that works on the same principles as mussels attaching to underwater surfaces and insects maintaining structural balance and flexibility.
Vital Protein in Healthy Fertilization Process Identified
Researchers at the National Institutes of Health have discovered a protein that plays a vital role in healthy egg-sperm union in mice.
Teeth Reveal Lifetime Exposures to Metals, Toxins
Researchers have identified dental biomarkers to reveal links between early iron exposure and late life brain diseases.
View of Bacterial Pump at the Atomic Level
Researchers have determined the structure of a simple but previously unexamined pump that controls the passage of proteins through a bacterial cell membrane, an achievement that offers new insight into the mechanics that allow bacteria to manipulate their environments.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,400+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!