Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > 'Nanoslinky': A Novel Nanofluidic Technology for DNA Manipulation and Measurement

Schematic showing the motion of a DNA molecule descending a nanofluidic staircase by entropophoresis (top). The illustration is overlaid on a micrograph of the actual staircase. Lightwave interference gives each step a different color. Corresponding fluorescence micrographs (bottom) show how the DNA molecule contracts as the depth increases from about 4 nanometers (about 20 times bigger than a water molecule) at the left to about 342 nanometers at the deepest step on the right. The images of the DNA molecule are blurred and pixilated, making it appear larger than it is. These imaging errors are estimated and corrected in the final analysis of the size of the molecule.

Credit: Strychalski, Stavis/NIST
Schematic showing the motion of a DNA molecule descending a nanofluidic staircase by entropophoresis (top). The illustration is overlaid on a micrograph of the actual staircase. Lightwave interference gives each step a different color. Corresponding fluorescence micrographs (bottom) show how the DNA molecule contracts as the depth increases from about 4 nanometers (about 20 times bigger than a water molecule) at the left to about 342 nanometers at the deepest step on the right. The images of the DNA molecule are blurred and pixilated, making it appear larger than it is. These imaging errors are estimated and corrected in the final analysis of the size of the molecule.

Credit: Strychalski, Stavis/NIST

Abstract:
Remember Slinky®, the coiled metal spring that "walks" down stairs with just a push, momentum and gravity? Researchers at the National Institute of Standards and Technology (NIST) have developed their own version of this classic—albeit 10 million times smaller—as a novel technology for manipulating and measuring DNA molecules and other nanoscale (billionth of a meter) materials.

'Nanoslinky': A Novel Nanofluidic Technology for DNA Manipulation and Measurement

Gaithersburg, MD | Posted on March 20th, 2012

In the first of two recent papers,* Samuel Stavis, Elizabeth Strychalski and colleagues demonstrated that a nanoscale fluidic channel shaped like a staircase with many steps (developed previously at NIST and Cornell University**) can be used to control the otherwise random drift of a DNA molecule through a fluid. Squeezed into the shallowest step at the top of the staircase, a strand of DNA diffuses randomly across that step. The DNA molecule seeks to increase its entropy—the universal tendency towards disorder in a system—by relieving its confinement, and therefore, "walks" down onto the next deeper step when it reaches the edge. The motion of the molecule down the staircase, which the researchers termed "entropophoresis" (entropy-driven transport), ends when it becomes trapped on the deepest step at the bottom. Because this motion resembles that of a Slinky®, the researchers nicknamed their system the "nanoslinky." The researchers found that DNA molecules of different sizes and shapes descended the staircase at different rates—which suggests the structure could be used to separate, concentrate and organize mixtures of nanoscale objects.

Stavis says that this novel technology provides advantages over traditional nanofluidic methods for manipulating and measuring DNA. "Control over the behavior of a DNA molecule is built into the staircase structure. After placing the molecule on the top step [by driving the DNA strand up the staircase with an electric field], no external forces are needed to make it move," Stavis says. "The staircase is a passive nanofluidic technology that automates complex manipulations and measurements of DNA."

This NIST advance in nanofluidic technology dovetails nicely with a NIST innovation in measurement science—specifically, determining the size of a DNA molecule in nanofluidic "slitlike confinement" imposed by the narrow gap between the floor of each step and the ceiling of the channel. In the "nanoslinky" system, Strychalski explains, the coiled and folded DNA strand contracts progressively as it moves down the steps. "Because there are many steps, we can make more detailed measurements than previous studies," she says.

Getting the most from those measurements was the goal of the research reported in the NIST team's second paper. *** "The challenge was to make our measurements of DNA size more quantitative," Strychalski says.

Previous measurements of DNA dimensions in nanofluidic systems, Strychalski says, have been limited by imaging errors from the optical microscopes used to measure the dimensions of DNA molecules labeled with a fluorescent dye. "The first problem is the diffraction limit, or the optical resolution, of the fluorescence microscope," she says. "The second problem is the pixel resolution of the camera. Because a DNA molecule is not much larger than the wavelength of light and the effective pixel size, images of fluorescent DNA molecules are blurred and pixilated, and this increases the apparent size of the molecule."

To improve their measurements of DNA molecules during their descent, the NIST researchers used models to approximate the effects of diffraction and pixilation. Applying these "numerical simulations" to the images of DNA molecules confined by the staircase made the final measurements of DNA size the most quantitative to date. These measurements also showed that more work is needed to fully understand this complicated system.

According to Stavis and Strychalski, the staircase is a simple prototype of a new class of engineered nanofluidic structures with complex three-dimensional surfaces. With further refinements, the technology may someday be mass produced for measuring and manipulating not just DNA molecules, but other types of biopolymers and nanoscale materials for health care and nanomanufacturing.

Slinky® is a registered trademark of POOF-Slinky, Inc.

* S.M. Stavis, J. Geist, M. Gaitan, L.E. Locascio and E.A. Strychalski. DNA molecules descending a nanofluidic staircase by entropophoresis. Lab on a Chip (2012). DOI: 10.1039/c21c21152a.

** See the April 7, 2009, Tech Beat article "World's First Nanofluidic Device with Complex 3-D Surfaces Built" at www.nist.gov/public_affairs/tech-beat/tb20090407.cfm#nanofluidic.

*** E.A. Strychalski, J. Geist, M. Gaitan, L.E. Locascio and S.M. Stavis. Quantitative measurements of the size scaling of linear and circular DNA in nanofluidic slitlike confinement. Macromolecules (2012). DOI: 10.1021/ma202559k.

####

About National Institute of Standards and Technology (NIST)
The National Institute of Standards and Technology (NIST) is an agency of the U.S. Department of Commerce.

For more information, please click here

Contacts:
Michael E. Newman
301-975-3025

Copyright © National Institute of Standards and Technology (NIST)

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

ICN2 researchers compute unprecedented values for spin lifetime anisotropy in graphene November 17th, 2017

Math gets real in strong, lightweight structures: Rice University researchers use 3-D printers to turn century-old theory into complex schwarzites November 16th, 2017

The stacked color sensor: True colors meet minimization November 16th, 2017

Nanometrics to Participate in the 6th Annual NYC Investor Summit 2017 November 16th, 2017

Laboratories

Ames Laboratory, UConn discover superconductor with bounce October 25th, 2017

Nanotube fiber antennas as capable as copper: Rice University researchers show their flexible fibers work well but weigh much less October 23rd, 2017

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Injecting electrons jolts 2-D structure into new atomic pattern: Berkeley Lab study is first to show potential of energy-efficient next-gen electronic memory October 13th, 2017

Microfluidics/Nanofluidics

Using light to propel water : With new method, MIT engineers can control and separate fluids on a surface using only visible light April 25th, 2017

Nano-SPEARs gently measure electrical signals in small animals: Rice University's tiny needles simplify data gathering to probe diseases, test drugs April 17th, 2017

Particle Works creates range of high performance quantum dots February 23rd, 2017

DNA 'barcoding' allows rapid testing of nanoparticles for therapeutic delivery February 7th, 2017

Govt.-Legislation/Regulation/Funding/Policy

EC Project Aims at Creating and Commercializing Cyber-Physical-System Solutions November 14th, 2017

Nanobiotix presented new clinical and pre-clinical data confirming NBTXR3’s significant potential role in Immuno-Oncology at SITC Annual Meeting November 14th, 2017

Leti Joins DARPA-Funded Project to Develop Implantable Device for Restoring Vision November 9th, 2017

Nanoshells could deliver more chemo with fewer side effects: In vitro study verifies method for remotely triggering release of cancer drugs November 8th, 2017

Nanomedicine

Nanobiotix presented new clinical and pre-clinical data confirming NBTXR3’s significant potential role in Immuno-Oncology at SITC Annual Meeting November 14th, 2017

Arrowhead to Present at 29th Annual Piper Jaffray Healthcare Conference November 14th, 2017

A new way to mix oil and water: Condensation-based method developed at MIT could create stable nanoscale emulsions November 8th, 2017

Nanoshells could deliver more chemo with fewer side effects: In vitro study verifies method for remotely triggering release of cancer drugs November 8th, 2017

Discoveries

ICN2 researchers compute unprecedented values for spin lifetime anisotropy in graphene November 17th, 2017

Math gets real in strong, lightweight structures: Rice University researchers use 3-D printers to turn century-old theory into complex schwarzites November 16th, 2017

The stacked color sensor: True colors meet minimization November 16th, 2017

Counterfeits and product piracy can be prevented by security features, such as printed 3-D microstructures: Forgeries and product piracy are detrimental to society and industry -- 3-D microstructures can increase security -- KIT researchers develop innovative fluorescent 3-D stru November 15th, 2017

Announcements

ICN2 researchers compute unprecedented values for spin lifetime anisotropy in graphene November 17th, 2017

Math gets real in strong, lightweight structures: Rice University researchers use 3-D printers to turn century-old theory into complex schwarzites November 16th, 2017

The stacked color sensor: True colors meet minimization November 16th, 2017

Nanometrics to Participate in the 6th Annual NYC Investor Summit 2017 November 16th, 2017

Nanobiotechnology

Nanobiotix presented new clinical and pre-clinical data confirming NBTXR3’s significant potential role in Immuno-Oncology at SITC Annual Meeting November 14th, 2017

Arrowhead to Present at 29th Annual Piper Jaffray Healthcare Conference November 14th, 2017

Nanoshells could deliver more chemo with fewer side effects: In vitro study verifies method for remotely triggering release of cancer drugs November 8th, 2017

Age-old malaria treatment found to improve nanoparticle delivery to tumors: Nanomedicine researchers find new use for 70-year-old drug November 7th, 2017

Research partnerships

EC Project Aims at Creating and Commercializing Cyber-Physical-System Solutions November 14th, 2017

Leti Joins DARPA-Funded Project to Develop Implantable Device for Restoring Vision November 9th, 2017

Nanoshells could deliver more chemo with fewer side effects: In vitro study verifies method for remotely triggering release of cancer drugs November 8th, 2017

Ames Laboratory, UConn discover superconductor with bounce October 25th, 2017

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