Nav: Home

A new way to stretch DNA

March 01, 2016

WASHINGTON, D.C., March 1, 2016 -- If you give a toy to a baby, she might investigate its properties by squeezing, throwing or chewing it. Scientists can similarly investigate the properties of materials by applying different forces, albeit in a much more controlled way.

Researchers have recently developed a new and improved way to controllably manipulate materials, in this case biomolecules that are far too small to see with the naked eye. By stretching molecules like DNA and proteins, scientists can find out important information about the structure, chemical bonding and mechanical properties of the individual molecules that make up our bodies. This understanding could shed light on diseases like cancer and amyotrophic lateral sclerosis (ALS).

The new technique is called acoustic force spectroscopy (AFS). The research team first described AFS in a 2015 Nature Methods paper and have since then upgraded it so that it is compatible with more imaging techniques, can produce a stronger stretching force, and can stretch from a designated distance. The researchers dubbed the upgrade AFS 2.0 and they will present it at the annual meeting of the Biophysical Society, held Feb. 27 - March 1 in Los Angeles, Calif.

"AFS is a new and promising technique that still has some tricks up his sleeve," said Douwe Kamsma, a graduate student in biophysics at the VU University in Amsterdam who was an author on the first AFS paper and is currently working on AFS 2.0.

AFS works by using sound waves to generate forces in a fluid channel. The fluidic channel is located in a glass slide and a piezo element is glued on top of the slide. The sound waves are produced by the piezo element, which vibrates in response to an applied alternating voltage. Researchers can tune the frequency to bring the system in resonance and make a standing wave. A standing wave is a wave in which specific points, called nodes, appear to be standing still.

To stretch DNA or other molecules, the researchers tether one end to the surface of the fluid channel and attach the other end to a microsphere. When the piezo element is turned on to create a standing wave in the fluid layer, the microspheres are forced toward the nodes of the standing waves. The selected resonance frequency of the wave determines the direction of the force and the amplitude determines the strength of the force. Researchers can change these two parameters almost instantaneously to manipulate the microspheres, and hence tug the DNA with varying degrees of force.

"The big advantage of AFS is that we can coat the whole surface with these tethered constructs and so measure thousands of single biomolecules in parallel," Kamsma said.

AFS 1.0 has already been commercialized by LUMICKS, which is a spinoff company from the VU University lab where Kamsma works. To upgrade the product to AFS 2.0, the researchers integrated an optically transparent piezo element, which would not block the view of the channel, and demonstrated that the AFS chip was compatible with a wide range of microscopes.

They also developed a model to optimize the thicknesses of the different system layers, making it possible to apply higher forces. Finally, they demonstrated a fast and easy method to quantify the force profile within the fluid layer, and showed that the AFS system could be used to stretch molecules by manipulating the distance of the attachments points of the biomolecule, a function called a distance clamp.

A distance clamp is better than a force clamp in probing multiple rupture events on the same molecule, Kamsma said. This could be used, for example, to study the overstretching of DNA as well as protein unfolding, he said.

"AFS is a very good example where the instruments and techniques that are developed by physicists are used to study cells and biomolecules," Kamsma said. To make the system work required knowledge from fluid dynamics, software development, manufacturing and molecular biology. "Bringing all this together is very exciting," he said. Most of the technical challenges of developing the new tool have been overcome, so "now is the time to apply it to very exciting biomolecular problems."

Presentation #2472, "Tuning the music: Acoustic force spectroscopy (AFS) 2.0.," is authored by Douwe Kamsma, Ramon Creyghton, Gerrit Sitters, Erwin J.G. Peterman and Gijs J.L. Wuite. It will be in a poster session that begins at 1:30 p.m. PT on Tuesday, March 1, 2016 in the West Hall of the Los Angeles Convention Center. ABSTRACT:

Each year, the Biophysical Society Annual Meeting brings together more than 6,500 researchers working in the multidisciplinary fields representing biophysics. With more than 3,600 poster presentations, over 200 exhibits, and more than 20 symposia, the BPS Annual Meeting is the largest meeting of biophysicists in the world. Despite its size, the meeting retains its small-meeting flavor through its subgroup symposia, platform sessions, social activities and committee programs. The 60th Annual Meeting will be held at the Los Angeles Convention Center.


The Biophysical Society invites professional journalists, freelance science writers and public information officers to attend its Annual Meeting free of charge. For press registration, contact Ellen Weiss <> or the media line at the American Institute of Physics at <> or 301-209-3090.


Embargoed press releases describing in detail some of the breakthroughs to be discussed at the meeting are available on Eurekalert, Newswise and Alpha Galileo or by contacting the media line at the American Institute of Physics at <> or 301-209-3090.


Main Meeting Page:
Itinerary planner:


The Biophysical Society, founded in 1958, is a professional, scientific Society established to encourage development and dissemination of knowledge in biophysics. The Society promotes growth in this expanding field through its annual meeting, monthly journal, and committee and outreach activities. Its 9,000 members are located throughout the U.S. and the world, where they teach and conduct research in colleges, universities, laboratories, government agencies, and industry. For more information on the Society, or the 2016 Annual Meeting, visit

Biophysical Society

Related Dna Articles:

A new twist on DNA origami
A team* of scientists from ASU and Shanghai Jiao Tong University (SJTU) led by Hao Yan, ASU's Milton Glick Professor in the School of Molecular Sciences, and director of the ASU Biodesign Institute's Center for Molecular Design and Biomimetics, has just announced the creation of a new type of meta-DNA structures that will open up the fields of optoelectronics (including information storage and encryption) as well as synthetic biology.
Solving a DNA mystery
''A watched pot never boils,'' as the saying goes, but that was not the case for UC Santa Barbara researchers watching a ''pot'' of liquids formed from DNA.
Junk DNA might be really, really useful for biocomputing
When you don't understand how things work, it's not unusual to think of them as just plain old junk.
Designing DNA from scratch: Engineering the functions of micrometer-sized DNA droplets
Scientists at Tokyo Institute of Technology (Tokyo Tech) have constructed ''DNA droplets'' comprising designed DNA nanostructures.
Does DNA in the water tell us how many fish are there?
Researchers have developed a new non-invasive method to count individual fish by measuring the concentration of environmental DNA in the water, which could be applied for quantitative monitoring of aquatic ecosystems.
Zigzag DNA
How the cell organizes DNA into tightly packed chromosomes. Nature publication by Delft University of Technology and EMBL Heidelberg.
Scientists now know what DNA's chaperone looks like
Researchers have discovered the structure of the FACT protein -- a mysterious protein central to the functioning of DNA.
DNA is like everything else: it's not what you have, but how you use it
A new paradigm for reading out genetic information in DNA is described by Dr.
A new spin on DNA
For decades, researchers have chased ways to study biological machines.
From face to DNA: New method aims to improve match between DNA sample and face database
Predicting what someone's face looks like based on a DNA sample remains a hard nut to crack for science.
More DNA News and DNA Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Warped Reality
False information on the internet makes it harder and harder to know what's true, and the consequences have been devastating. This hour, TED speakers explore ideas around technology and deception. Guests include law professor Danielle Citron, journalist Andrew Marantz, and computer scientist Joy Buolamwini.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

How to Win Friends and Influence Baboons
Baboon troops. We all know they're hierarchical. There's the big brutish alpha male who rules with a hairy iron fist, and then there's everybody else. Which is what Meg Crofoot thought too, before she used GPS collars to track the movements of a troop of baboons for a whole month. What she and her team learned from this data gave them a whole new understanding of baboon troop dynamics, and, moment to moment, who really has the power.  This episode was reported and produced by Annie McEwen. Support Radiolab by becoming a member today at