Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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

Dr Barbara Armbruster promoted to Worldwide Sales and Marketing Director for XEI Scientific September 27th, 2016

Fighting cancer with sticky nanoparticles September 27th, 2016

Gold nanoparticles conjugated quercetin inhibits epithelial-mesenchymal transition, angiogenesis and invasiveness via EGFR/VEGFR-2 mediated pathway in breast cancer September 27th, 2016

UNAM develops successful nano edible coating which increases life food September 27th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Tattoo therapy could ease chronic disease: Rice-made nanoparticles tested at Baylor College of Medicine may help control autoimmune diseases September 23rd, 2016

PHENOMEN is a FET-Open Research Project aiming to lay the foundations a new information technology September 19th, 2016

NIST Patents Single-Photon Detector for Potential Encryption and Sensing Apps September 16th, 2016

Possible Futures

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Researchers at the Catalan Institute of Nanoscience and Nanotechnology show that bending semiconductors generates electricity September 26th, 2016

Chains of nanogold – forged with atomic precision September 23rd, 2016

Tattoo therapy could ease chronic disease: Rice-made nanoparticles tested at Baylor College of Medicine may help control autoimmune diseases September 23rd, 2016

Academic/Education

PHENOMEN is a FET-Open Research Project aiming to lay the foundations a new information technology September 19th, 2016

AIM Photonics Announces Release of Process Design Kit (PDK) for Integrated Silicon Photonics Design August 25th, 2016

Nanotech Security Featured by Simon Fraser University: Company's Anti-Counterfeiting Technology Developed With the Help of University's 4D LABS Materials Research Institute August 21st, 2016

W.M. Keck Foundation awards Cal State LA a $375,000 research and education grant August 4th, 2016

Nanomedicine

Fighting cancer with sticky nanoparticles September 27th, 2016

Gold nanoparticles conjugated quercetin inhibits epithelial-mesenchymal transition, angiogenesis and invasiveness via EGFR/VEGFR-2 mediated pathway in breast cancer September 27th, 2016

Tattoo therapy could ease chronic disease: Rice-made nanoparticles tested at Baylor College of Medicine may help control autoimmune diseases September 23rd, 2016

BBI Solutions launches innovative conjugate blocking technology that enhances signal intensity for lateral flow immunoassays September 20th, 2016

Announcements

Dr Barbara Armbruster promoted to Worldwide Sales and Marketing Director for XEI Scientific September 27th, 2016

Fighting cancer with sticky nanoparticles September 27th, 2016

Gold nanoparticles conjugated quercetin inhibits epithelial-mesenchymal transition, angiogenesis and invasiveness via EGFR/VEGFR-2 mediated pathway in breast cancer September 27th, 2016

UNAM develops successful nano edible coating which increases life food September 27th, 2016

Nanobiotechnology

Fighting cancer with sticky nanoparticles September 27th, 2016

Gold nanoparticles conjugated quercetin inhibits epithelial-mesenchymal transition, angiogenesis and invasiveness via EGFR/VEGFR-2 mediated pathway in breast cancer September 27th, 2016

Tattoo therapy could ease chronic disease: Rice-made nanoparticles tested at Baylor College of Medicine may help control autoimmune diseases September 23rd, 2016

BBI Solutions launches innovative conjugate blocking technology that enhances signal intensity for lateral flow immunoassays September 20th, 2016

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







Car Brands
Buy website traffic