Corporate Banner
Satellite Banner
Technology
Networks
Scientific Communities
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Observing Behavior of Single Molecules in Real Time

Published: Monday, March 17, 2014
Last Updated: Monday, March 17, 2014
Bookmark and Share
New technique developed by Stanford scientists allows observation of single molecules of protein or DNA as they bind with other molecules.

Nearly every biological or chemical reaction that makes life possible involves single molecules interacting in the watery solution that sloshes in and around cells.

Now, a Stanford chemistry professor and his graduate student have developed a technique for observing these processes as they happen in real time.

W.E. Moerner, a professor of chemistry, specializes in single molecule fluorescence, a field that involves studying how biomolecules – such as DNA and enzymes – work in cells to carry out the processes that are critical to life. The new advance describes how Moerner and his graduate student, Quan Wang, modified an ABEL (Anti-Brownian ELectrokinetic) trap, a machine invented in Moerner's lab that uses electric fields to manipulate individual small molecules from the light they emit, to isolate a single strand of DNA and observe how it binds to other DNA, in aqueous solution.

The work is detailed in the journal Nature Methods.

Getting this process started takes a little bit of luck, Wang said, as they must wait until a single molecule happens to be in the vicinity of the trap. This all happens at an incredibly tiny scale. The trap covers about a square centimeter, but the molecules are just 1 nanometer long. (For perspective, that's trapping a single grain of pollen on a football field, and then, without ever touching it, studying its behavior and characteristics.)

Once a lone molecule has entered the trap, its motion comes under continuous surveillance. Although the molecule doesn't want to sit still, every time it attempts to escape, the ABEL trap automatically applies electric fields to push it back.

Using physical analysis and computational tricks from machine learning, Wang developed an algorithm to convert the observed single-molecule motions inside the trap into information about the molecule's size and electric charge. From this, the researchers can determine whether the target molecule has interacted with another molecule.

In the case of DNA, if it begins to hybridize – that is, if it begins to bond to a complementary strand of DNA – the readings from the trap will show that the trapped DNA has an increase in both size and charge. When the process reverses a few instants later – that is, when the DNA melts and its complementary strand falls off – the trapped molecule's size and charge change back correspondingly.

"It is really quite amazing to be able to trap a single short piece of single-stranded DNA, to watch it for many seconds and directly observe a partner strand bind and unbind," Moerner said. "This is really an essential process."

The researchers conducted similar tests using proteins, and Wang said that the technology in its current state can easily be applied to many different types of molecules to study other binding processes.

"We've done the proof of concept for the method, and soon we want to apply it to two very specific problems and get some science out of it," said Wang, who is a graduate student in electrical engineering.

The first involves drug design. Drugs target diseases by binding to receptor molecules on cells, and the drug's effectiveness often depends on how well and for how long it binds to its receptor. By gauging the size and total charge of the molecules as they form a complex, the trap can directly measure how long it takes for the drug to find its receptor and how long the complex stays together. This information could guide scientists toward designing drugs that better match their target receptor.

Another application is to study the role protein aggregation plays in various diseases. As people age, proteins can become "sticky" and accumulate, a hallmark of several diseases, including Huntington's. The trap provides a direct way to study the size distribution of these proteins and how they aggregate; understanding this effect could lead to treatments that inhibit it.

Other students and postdoctoral scholars in Moerner's group are working to make the trap respond even more quickly, to perform more optimally in other situations, or to study different properties of single molecules. Moerner said that the interdisciplinary makeup of his group (including him; he holds a degree in electrical engineering as well as in chemistry) is critical for understanding all the different facets of this work, and then for smart implementation of it.

"We use light to probe molecules – that's physics and chemistry," Moerner said. "And we apply it to biology and biomedical systems. But at the core is precise measurement, extracting as much information as possible from a single object, and that can be done with concepts from electrical engineering.

"It's a natural thing at Stanford for students in one department to do thesis research in another. It's one of the wonderful aspects at Stanford, and it can lead to wonderful work such as this."


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,900+ scientific posters on ePosters
  • More Than 4,200+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Flexible Gene Expression May Regulate Social Status
Scientists show how the selective expression of genes through epigenetics can regulate the social status of African cichlid fish.
Monday, January 11, 2016
World Forest Carbon Stocks Overestimated
Researchers with The Natural Capital Project show how fragmentation harms forests' ability to store carbon; more restoration is needed to reconnect forest patches.
Tuesday, January 05, 2016
U.S. Needs a New Approach for Governance of Risky Research
The United States needs better oversight of risky biological research to reduce the likelihood of a bioengineered super virus escaping from the lab or being deliberately unleashed, according three Stanford scholars.
Monday, January 04, 2016
Mapping the Mechanical Properties of Living Cells
Researchers have developed a new way to use atomic force microscopy to rapidly measure the mechanical properties of cells at the nanometer scale, an advance that could pave the way for better understanding immune disorders and cancer.
Monday, December 21, 2015
Viral Infections Leave a Signature on the Immune System
A test that queries the body’s own cells can distinguish a viral infection from a bacterial infection and could help doctors know when to use antibiotics.
Thursday, December 17, 2015
Novel Approach to Understanding Brain Function
Russell Poldrack scanned his brain to create the most detailed map of brain connectivity ever.
Monday, December 14, 2015
Accelerating Protein Evolution
A new tool enables researchers to test millions of mutated proteins in a matter of hours or days, speeding the search for new medicines, industrial enzymes and biosensors.
Monday, December 14, 2015
Blocking Dengue Fever Virus
By targeting fundamental cellular machinery, the antiviral approach developed in Judith Frydman's lab at Stanford could provide a roadmap to preventing infections that affect hundreds of millions of people every year.
Thursday, December 03, 2015
Gene Linked to Heart Failure
Researchers have identified a previously unknown association between heart function and the narcolepsy-linked orexin receptor pathway, a finding that could provide a promising direction for treatment research.
Wednesday, December 02, 2015
New Class of RNA Tumor Suppressors Identified
Two short, “housekeeping” RNA molecules block cancer growth by binding to an important cancer-associated protein called KRAS. More than a quarter of all human cancers are missing these RNAs.
Thursday, November 26, 2015
Ancient Viral Molecules Essential for Human Development
Genetic material from ancient viral infections is critical to human development, according to researchers at the Stanford University School of Medicine.
Wednesday, November 25, 2015
Sleep Deprivation Affects Stem Cells, Reducing Transplant Efficiency
Although the research was done in mice, the findings have possible implications for bone marrow transplants, more properly called hematopoietic stem cell transplants, in humans.
Friday, October 16, 2015
Enzyme Malfunction May be Why Binge Drinking Can Lead to Alcoholism
A new study in mice shows that restoring the synthesis of a key brain chemical tied to inhibiting addictive behavior may help prevent alcohol cravings following binge drinking.
Friday, October 09, 2015
How Cell Growth Triggers Cell Division
Researchers in Jan Skotheim's lab have discovered a previously unknown mechanism that controls how large cells grow, an insight that could one day provide insight into attacking diseases such as cancer.
Wednesday, October 07, 2015
Tension Helps Heart Cells Develop Normally in the Lab
Stanford engineers have uncovered the important role tension plays in growing heart cells out of the body.
Monday, October 05, 2015
Scientific News
Breaking Cell Barriers with Retractable Protein Nanoneedles
Adapting a bacterial structure, institute researchers have developed protein actuators that can mechanically puncture cells.
Gene Signature could Lead to a New Way of Diagnosing Lyme Disease
Lyme disease patients had distinctive gene signatures that persisted for at least three weeks, even after they had taken the antibiotics.
Retractable Protein Nanoneedles
The ability to control the transfer of molecules through cellular membranes is an important function in synthetic biology; a new study from researchers at Harvard’s Wyss Institute for Biologically Inspired Engineering and Harvard Medical School (HMS) introduces a novel mechanical method for controlling release of molecules inside cells.
Leukemia’s Surroundings Key to its Growth
Researchers at The University of Texas at Austin have discovered that a type of cancer found primarily in children can grow only when signaled to do so by other nearby cells that are noncancerous.
Common Cell Transformed into Master Heart Cell
By genetically reprogramming the most common type of cell in mammalian connective tissue, researchers at the University of Wisconsin—Madison have generated master heart cells — primitive progenitors that form the developing heart.
‘Smelling’ Prostate Cancer
A research team from the University of Liverpool and the University of the West of England (UWE Bristol) has reached an important milestone towards creating a urine diagnostic test for prostate cancer that could mean that invasive diagnostic procedures that men currently undergo eventually become a thing of the past.
Genetic Mutation that Prevents Diabetes Complications
The most significant complications of diabetes include diabetic retinal disease, or retinopathy, and diabetic kidney disease, or nephropathy. Both involve damaged capillaries.
A Crystal Clear View of Biomolecules
Fundamental discovery triggers paradigm shift in crystallography.
Could the Food we Eat Affect Our Genes?
Almost all of our genes may be influenced by the food we eat, according to new research.
NIH Seeks Research Applications to Study Zika in Pregnancy, Developing Fetus
Institute has announced that the new effort seeks to understand virus effect on reproduction and child development.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,900+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,200+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!