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

Join For Free

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 3,200+ scientific posters on ePosters
  • More than 4,600+ 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

Controlling RNA in Living Cells
Modular, programmable proteins can be used to track or manipulate gene expression.
Wednesday, April 27, 2016
Why Some Tumors Withstand Treatment
Mechanism uncovered that allows cancer cells to evade targeted therapies.
Thursday, March 17, 2016
Paving the Way for Metastasis
Cancer cells remodel their environment to make it easier to reach nearby blood vessels.
Tuesday, March 15, 2016
Synthetic Antibody Detects Proteins
Research could lead to nanosensors that recognize fibrinogen, insulin, or other biomarkers.
Friday, January 15, 2016
New Device Uses Carbon Nanotubes to Snag Molecules
Nanotube “forest” in a microfluidic channel may help detect rare proteins and viruses.
Tuesday, December 22, 2015
CRISPR-Cas9 Genome Editing Hurdle Overcome
Team re-engineers system to dramatically cut down on editing errors; improvements advance future human applications.
Thursday, December 03, 2015
A Natural Light Switch
MIT scientists identify and map the protein behind a light-sensing mechanism.
Tuesday, September 29, 2015
Biologists Find Unexpected Role for Amyloid-Forming Protein
Yeast protein could offer clues to how Alzheimer’s plaques form in the brain.
Monday, September 28, 2015
How Flu Viruses Gain The Ability To Spread
New study reveals the soft palate is a key site for evolution of airborne transmissibility.
Friday, September 25, 2015
Targeting DNA
Protein-based sensor could detect viral infection or kill cancer cells.
Tuesday, September 22, 2015
Targeting DNA
Protein-based sensor could detect viral infection or kill cancer cells.
Tuesday, September 22, 2015
Learning About Human Health Using Sewage
PhD student Mariana Matus studies human waste to understand individual and community health.
Thursday, September 17, 2015
Protein Found to Play a Key Role in Blocking Pathogen Survival
Calprotectin fends off microbial invaders by limiting access to iron, an important nutrient.
Wednesday, August 26, 2015
Real-Time Data for Cancer Therapy
Biochemical sensor implanted at initial biopsy could allow doctors to better monitor and adjust cancer treatments.
Thursday, August 06, 2015
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
Scientific News
ASMS 2016: Targeting Mass Spectrometry Tools for the Masses
The expanding application range of MS in life sciences, food, energy, and health sciences research was highlighted at this year's ASMS meeting in San Antonio, Texas.
Proteins in Blood of Heart Disease Patients May Predict Adverse Events
Nine-protein test shown superior to conventional assessments of risk.
Self-Assembling Protein Shell for Drug Delivery
Made-to-order nano-cages open possibilities of shipping cargo into living cells or fashioning small chemical reactors.
Molecular Map Provides Clues To Zinc-Related Diseases
Mapping the molecular structure where medicine goes to work is a crucial step toward drug discovery against deadly diseases.
Nanoprobe Enables Measurement of Protein Dynamics in Living Cells
Mass. General and Harvard researchers use device to measure how anesthetic affects levels of Alzheimer's-associated proteins.
Diagnosing Systemic Infections Quickly, Reliably
Team develop rapid and specific diagnostic assay that could help physicians decide within an hour whether a patient has a systemic infection and should be hospitalized for aggressive intervention therapy.
What Makes a Good Scientist?
It’s the journey, not just the destination that counts as a scientist when conducting research.
A New Tool Brings Personalized Medicine Closer
Scientists from EPFL and ETHZ have developed a powerful tool for exploring and determining the inherent biological differences between individuals, which overcomes a major hurdle for personalized medicine.
Blood Test That Detects Early Alzheimer’s Disease
A research team, led by Dr. Robert Nagele from Rowan University School of Osteopathic Medicine and Durin Technologies, Inc., has announced the development of a blood test that leverages the body’s immune response system to detect an early stage of Alzheimer’s disease – referred to as the mild cognitive impairment (MCI) stage – with unparalleled accuracy.
‘Missing Tooth’ Hydrogels Handle Hard-to-Deliver Drugs
Rice University’s custom hydrogel traps water-avoiding molecules for slow delivery.
Scroll Up
Scroll Down
SELECTBIO

SELECTBIO Market Reports
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
3,200+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,600+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!