submit news    HOME | FEEDBACK  


- Bio/Medicine

- Chemicals

- Defense

- Drug Delivery

- Education

- Electronics

- Energy

- Events

- Grants

- Industry

- Investment

- Litigation

- Materials


- Nanofabrication

- Nanoparticles

- Nanotubes

- Optics

- Partnership

- Patent

- Products

- Quantum dots

- Research

- Smart Dust

- Software

- Browse by Month

- Current Shows

- Previous Shows

- Submit Events

Become A Nanotechwire Partner

FEI Company

Veeco Instruments

Nano Science and Technology Institute

National Nanotechnology Initiative

Nanotechnology at Zyvex

Want to see your Company or Organization listed above? Become A Nanotechwire Partner Today - click here


5/27/2007 10:24:45 AM
New Method Weighs Single Living Cells, Nanoparticles, Even Molecules

For the first time, researchers at the Massachusetts Institute of Technology (MIT) have found a way to measure the mass of single cells with high accuracy. The new technique, which uses microfluidics and a nanoscale device known as a cantilever, could allow researchers to develop inexpensive, portable diagnostic devices and might also offer a unique glimpse into how cells change as they undergo cell division.

Unlike conventional methods, the MIT technique allows cells to remain in fluid while they are being measured, opening up a new realm of possible applications, says Scott Manalis, Ph.D., who led the team of investigators that built this nanosize scale and published its results in the journal Nature.

In addition to weighing cells, the technology can be used to weigh nanoparticles or biomolecules. Current mass measurement methods achieve a resolution down to a zeptogram (10-21 grams) but only work with nonliving things because the procedure must be performed inside a vacuum. So, the MIT researchers decided to turn the conventional system inside out.

In the traditional method, the molecules to be weighed are placed on top of a tiny slab, or cantilever, made of silicon. The slab vibrates at its resonant frequency (the frequency at which the material naturally tends to vibrate) inside a vacuum. When a molecule sits on the slab, the frequency changes slightly, and the mass of the molecule can be calculated by measuring that change. This measurement must be performed in a vacuum to prevent air (or fluid) from interfering with the frequency of oscillation. However, cells cannot survive in a vacuum, so they must be measured in fluid, which diminishes the accuracy of the measurement.

The researchers solved this dilemma by placing the fluid containing the sample inside the silicon slab, which still oscillates within a vacuum surrounding it. The biological sample is pumped through a microchannel that runs across the slab, without impairing its ability to vibrate.

So far, the researchers have weighed particles with a resolution down to slightly below a femtogram (10-15 grams), but Manalis believes that, with refinements, the sensitivity could potentially be lowered by several orders of magnitude within a few years. "Every step along the way will open up new possibilities," he said.

Manalis is planning a collaboration with MIT colleague Angelika Amon, Ph.D., who is interested in studying how the mass density of a single cell changes as it goes through cell division. Using the new method, scientists can ultimately trap a single cell and observe it over a long period of time. Changes in mass could correlate to production of proteins, offering a new way to study what the cell does during division, Manalis said, and perhaps during uncontrolled cell division, the hallmark of cancer.

Another application of the new technology is to measure small particles, or beads. "It is important to know the size of particles used in paint, drug delivery devices, coatings, and nanocomposite materials," said Manalis, who added that the new technology could become the "gold standard" to measure these particles one by one.

This work is detailed in the paper "Weighing of biomolecules, single cells and single nanoparticles in fluid." Investigators from Innovative Micro Technology and Affinity Biosensors, both in Santa Barbara, CA, also participated in this study. An abstract of this paper is available through PubMed.

View abstract

Other Headlines from Massachusetts Institute of Technology ...
 - Toward faster transistors
 - New sensor developed by MIT chemical engineers can detect tiny traces of explosives
 - Catching cancer with carbon nanotubes
 - Seeing below the surface
 - Koch Institute for Integrative Cancer Research dedicated at MIT

Other Headlines from NCI Alliance for Nanotechnology in Cancer ...
 - Tekmira and the National Cancer Institute Publish Promising Data Demonstrating the Anti-Tumor Activity of a Novel Cancer Target
 - NCI Awards $1.7 Million to Cancer Specialist at Children’s Hospital Los Angeles
 - Nanoparticles Enhance Detection of Circulating Tumor Cells
 - Hand-held NMR Instrument Yields Rapid Analysis of Human Tumors
 - Biodegradable Biopolymer Nanoparticles Hold Promise for Twin Attack on Breast Cancer

More Research Headlines ...
 - Experiments Settle Long-Standing Debate about Mysterious Array Formations in Nanofilms
 - "Critical baby step" taken for spying life on a molecular scale
 - Seeing an atomic thickness
 - First-ever sub-nanoscale snapshots of renegade protein in Huntington's Disease
 - Karlsruhe Invisibility Cloak: Disappearing Visibly

« Back To List »

- submit company
- submit news
- submit events
- advertise here

- More Events

Copyright © 2017 | Privacy Policy |