Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > UPenn Scientists Develop Method for Detecting MicroRNA From Living Cells

Probe-microRNA duplexes translocate through thin nanopores. (Artwork: Robert Johnson)
Probe-microRNA duplexes translocate through thin nanopores. (Artwork: Robert Johnson)

Abstract:
Researchers at the University of Pennsylvania have developed a new electronic method for detecting microRNA isolated from living cells. MicroRNAs are a class of small biomolecules that control gene expression into proteins, the "workers" of the cell. MicroRNAs act by binding to specific messenger RNAs that code for proteins, and, by doing so, inhibit protein synthesis.

UPenn Scientists Develop Method for Detecting MicroRNA From Living Cells

Philadelphia, PA | Posted on October 26th, 2010

MicroRNAs, or miRNAs, were initially identified in roundworms in 1993. Since then, biologists have discovered that microRNAs control gene expression, and therefore there is immense interest in these molecules as potential therapeutics for silencing cancer and disease-related genes.

The problem with microRNA detection is that the number of copies of microRNA in cells is so small that detection is quite challenging. The team developed a method to fabricate nanopores in the thinnest silicon nitride membranes reported to date, about 6 nm thick.

First, the team showed that these nanopores increase the signal resolution from reading DNA molecules as they pass through the pores. After demonstrating the enhanced sensitivity, the Penn team needed a method to isolate a specific microRNA from cells.

They teamed with a group headed by Larry McReynolds of New England Biolabs.

"Larry and co-workers had a neat trick: they use a viral protein called p19 to tightly bind duplex RNA molecules of the exact dimensions of microRNAs," Meni Wanunu, a research associate at Penn, said. "So we devised a plan that uses this protein to isolate very small amounts of specific microRNAs that we can then quantify using our pores."

The team focused on detecting miR122a, a liver-specific microRNA in mammals.

They first demonstrated that their nanopores are reliable enough to quantify the concentrations of these tiny molecules that are only 22 bases long, or 6 nm in length. After having made ultrathin membranes by locally etching silicon nitride, the group used electron beams to drill the nanopores in the thinned portion of the silicon nitride membranes.

"Using 3 nm diameter pores, these duplex RNA molecules just squeeze through the pores and in doing so, each molecule produces a nice electronic signal," Wanunu said. "We were delighted, things worked out really nice. These are the smallest synthetic pores in all dimensions, and it is surprising how stable and robust they are. We now use them routinely for various investigations; they are our new state-of-the-art."

The article, featured on the cover of the November 2010 issue of Nature Nanotechnology, shows a duplex microRNA molecule passing through a very thin nanopore made at Penn.

"It is wonderful to see the expected improvements in signal to noise ratios using these thin nanopores," Marija Drndić, an associate professor of physics and the group leader on the project, said. "In spite of their being thin, they are quite robust, and they seem to function every time because they do not tend to trap hydrophobic contaminants and they allow unimpeded flow through them. All this makes them ideal candidates for various biophysical applications."

The Penn team is now working on specific methods for detecting other small molecules, as well as integrating these nanopores with fluidic systems to improve sensitivity.

The research was conducted by Wanunu, Drndić Tali Dadosh and Vishva Ray of Penn, and Jingmin Jin and McReynolds of New England Biolabs.

The research was supported by a National Institutes of Health grant and the Penn Genome Frontiers Institute of the Commonwealth of Pennsylvania and Pennsylvania Department of Health.

The Department of Health specifically disclaims responsibility for any analyses, interpretations or conclusions.

####

For more information, please click here

Contacts:
Jacquie Posey

215-898-8658

Copyright © University of Pennsylvania

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

CiQUS researchers design an artificial nose to detect DNA differentiation with single nucleotide resolution September 18th, 2014

Big Results Require Big Ambitions: Three young UCSB faculty receive CAREER awards from the National Science Foundation September 18th, 2014

FEI Opens New Technology Center in Czech Republic: FEI expands its presence in Brno with the opening of a new, larger facility September 18th, 2014

Biosensors Get a Boost from Graphene Partnership: $5 Million Investment Supports Dozens of Jobs and Development of 300mm Fabrication Process and Wafer Transfer Facility September 18th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Big Results Require Big Ambitions: Three young UCSB faculty receive CAREER awards from the National Science Foundation September 18th, 2014

Scientists refine formula for nanotube types: Rice University theorists determine factors that give tubes their chiral angles September 17th, 2014

New non-invasive technique could revolutionize the imaging of metastatic cancer September 17th, 2014

Recruiting bacteria to be technology innovation partners: September 17th, 2014

Possible Futures

Air Force’s 30-year plan seeks 'strategic agility' August 1st, 2014

IBM Announces $3 Billion Research Initiative to Tackle Chip Grand Challenges for Cloud and Big Data Systems: Scientists and engineers to push limits of silicon technology to 7 nanometers and below and create post-silicon future July 10th, 2014

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

Local girl does good March 22nd, 2014

Academic/Education

Biosensors Get a Boost from Graphene Partnership: $5 Million Investment Supports Dozens of Jobs and Development of 300mm Fabrication Process and Wafer Transfer Facility September 18th, 2014

Malvern technology delivers Malvern reliability in multi-disciplinary lab at Queen Mary University London September 9th, 2014

State University of New York Trustees Unanimously Approve SUNY Polytechnic Institute (SUNY Poly) as New Name for Merged SUNY CNSE / SUNYIT September 9th, 2014

New Vice President Takes Helm at CNSE CMOST: Catherine Gilbert To Lead CNSE Children’s Museum of Science and Technology Through Expansion And Relocation August 29th, 2014

Nanomedicine

The Pocket Project will develop a low-cost and accurate point-of-care test to diagnose Tuberculosis: ICN2 holds a follow-up meeting of the Project on September 18th - 19th September 18th, 2014

New non-invasive technique could revolutionize the imaging of metastatic cancer September 17th, 2014

Recruiting bacteria to be technology innovation partners: September 17th, 2014

Nanoscience makes your wine better September 17th, 2014

Announcements

Wear-resistant ceramic powder maximises component lifespan in high-stress applications: Innovnano’s nanostructured 3YSZ offers improved tribological performance for manufacturing components September 18th, 2014

IEEE International Electron Devices Meeting To Celebrate 60th Anniversary as The Leading Technical Conference for Advanced Semiconductor Devices September 18th, 2014

FEI Opens New Technology Center in Czech Republic: FEI expands its presence in Brno with the opening of a new, larger facility September 18th, 2014

Biosensors Get a Boost from Graphene Partnership: $5 Million Investment Supports Dozens of Jobs and Development of 300mm Fabrication Process and Wafer Transfer Facility September 18th, 2014

Nanobiotechnology

CiQUS researchers design an artificial nose to detect DNA differentiation with single nucleotide resolution September 18th, 2014

Biosensors Get a Boost from Graphene Partnership: $5 Million Investment Supports Dozens of Jobs and Development of 300mm Fabrication Process and Wafer Transfer Facility September 18th, 2014

Recruiting bacteria to be technology innovation partners: September 17th, 2014

NanoStruck has a High Recovery Rate on Mine Tailings: retrieval of up to 96% of Gold, 88% of Silver and 86% of Palladium September 12th, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE