Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

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

Laboratories

NREL Announces New Center Directors to lead R&D, Analysis Efforts September 30th, 2014

News and information

NREL Announces New Center Directors to lead R&D, Analysis Efforts September 30th, 2014

Yale University and Leica Microsystems Partner to Establish Microscopy Center of Excellence: Yale Welcomes Scientists to Participate in Core Facility Opening and Super- Resolution Workshops October 20 Through 31, 2014 September 30th, 2014

Speed at its limits September 30th, 2014

Research mimics brain cells to boost memory power September 30th, 2014

Microfluidics/Nanofluidics

Dolomite to launch Meros TCU-100 temperature controller at Lab-on-a-Chip & Microarray World Congress September 15th, 2014

First Colloid and Polymer Science Lecture awarded to Orlin D. Velev: Chemical engineer honored for outstanding research in colloid science September 12th, 2014

UO-Berkeley Lab unveil new nano-sized synthetic scaffolding technique: Oil-and-water approach from Richmond's UO lab to spark new line of versatile peptoid nanosheets September 2nd, 2014

Nanoscale assembly line August 29th, 2014

Govt.-Legislation/Regulation/Funding/Policy

NREL Announces New Center Directors to lead R&D, Analysis Efforts September 30th, 2014

A Heartbeat Away? Hybrid "Patch" Could Replace Transplants: TAU researcher harnesses gold nanoparticles to engineer novel biocompatible cardiac patch September 30th, 2014

How things coil: Researchers discover that simulation technology designed for Hollywood can be used as a predictive tool for understanding fundamental engineering problems September 29th, 2014

UT Arlington researchers develop transparent nanoscintillators for radiation detection for medical safety and homeland security September 29th, 2014

Nanomedicine

Speed at its limits September 30th, 2014

Ad-REIC vaccine: A magic bullet for cancer treatment September 30th, 2014

New Topical Hemostatic Agent: Neutral Self-Assembling Peptide Hydrogel September 30th, 2014

A Heartbeat Away? Hybrid "Patch" Could Replace Transplants: TAU researcher harnesses gold nanoparticles to engineer novel biocompatible cardiac patch September 30th, 2014

Discoveries

Research mimics brain cells to boost memory power September 30th, 2014

Ad-REIC vaccine: A magic bullet for cancer treatment September 30th, 2014

New Topical Hemostatic Agent: Neutral Self-Assembling Peptide Hydrogel September 30th, 2014

Chemical interactions between silver nanoparticles and thiols: A comparison of mercaptohexanol again September 30th, 2014

Announcements

Park Systems Announces Outsourced Analytical Services Including AFM Surface Imaging, Data Analysis and Interpretation September 30th, 2014

Ad-REIC vaccine: A magic bullet for cancer treatment September 30th, 2014

New Topical Hemostatic Agent: Neutral Self-Assembling Peptide Hydrogel September 30th, 2014

Chemical interactions between silver nanoparticles and thiols: A comparison of mercaptohexanol again September 30th, 2014

Nanobiotechnology

Ad-REIC vaccine: A magic bullet for cancer treatment September 30th, 2014

How things coil: Researchers discover that simulation technology designed for Hollywood can be used as a predictive tool for understanding fundamental engineering problems September 29th, 2014

Penn Team Studies Nanocrystals by Passing Them Through Tiny Pores September 26th, 2014

New NIH/DOE Grant for Life Science Studies at NSLS-II: Funding will support operation of three powerful experimental stations designed to reveal detailed structures of proteins, viruses, and more September 23rd, 2014

Research partnerships

Research mimics brain cells to boost memory power September 30th, 2014

'Pixel' engineered electronics have growth potential: Rice, Oak Ridge, Vanderbilt, Penn scientists lead creation of atom-scale semiconducting composites September 29th, 2014

Teijin Aramid’s carbon nanotube fibers awarded with Paul Schlack prize: New generation super fibers bring wave of innovations to fiber market September 25th, 2014

Smallest-possible diamonds form ultra-thin nanothread September 25th, 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