Featured Research

from universities, journals, and other organizations

Imaging dynamics of small biomolecules inside live cells

Date:
March 2, 2014
Source:
Columbia University
Summary:
A significant step has been made toward visualizing small biomolecules inside living biological systems with minimum disturbance, a longstanding goal in the scientific community. In a study, a research team describes its development of a general method to image a broad spectrum of small biomolecules, such as small molecular drugs and nucleic acids, amino acids, lipids for determining where they are localized and how they function inside cells.

Researchers at Columbia University have made a significant step toward visualizing small biomolecules inside living biological systems with minimum disturbance, a longstanding goal in the scientific community. In a study published March 2nd in Nature Methods, Assistant Professor of Chemistry Wei Min's research team has developed a general method to image a broad spectrum of small biomolecules, such as small molecular drugs and nucleic acids, amino acids, lipids for determining where they are localized and how they function inside cells.

When studying biological functions of a molecule in complex and mysterious cells, researchers typically label the molecules of interest with fluorophores, a kind of molecules that glow when illuminated. Using a fluorescence microscope, common in research labs, the fluorophore-tagged molecules can be located and tracked with high precision. The invention of green fluorescent protein (GFP), in 1994, compatible with imaging inside live cells and animals, has since made fluorescence microscopy even more popular.

However, when it comes to small biomolecules, fluorophore tagging is problematic, because the fluorophores are almost always larger or comparable in size to the small molecules of interest. As a result, they often disturb the normal functions of these small molecules with crucial biological roles.

To address this problem, Min and his team departed from the conventional paradigm of fluorescence imaging of fluorophores, and pursued a novel combination of physics and chemistry. Specifically, they coupled an emerging laser-based technique called stimulated Raman scattering (SRS) microscopy with a small but highly vibrant alkyne tag (that is, C=C, carbon-carbon triple bond), a chemical bond that, when it stretches, produces a strong Raman scattering signal at a unique "frequency" (different from natural molecules inside cells).

This new technique, labeling the small molecules with this tiny alkyne tag, avoids perturbation that occurs with large fluorescent tags, while obtaining high detection specificity and sensitivity by SRS imaging. By tuning the laser colors to the alkyne frequency and quickly scanning the focused laser beam across the sample, point-by-point, SRS microscopy can pick up the unique stretching motion of the C=C bond carried by the small molecules and produce a three-dimensional map of the molecules inside living cells and animals. In this way, Min's team demonstrated tracking alkyne-bearing drugs in mouse tissues and visualizing de novo synthesis of DNA, RNA, proteins, phospholipids and triglycerides through metabolic incorporation of alkyne-tagged small precursors in living cells.

"The major advantages of our technique lie in the superb sensitivity, specificity and biocompatibility with dynamics of live cells and animals for small molecule imaging," says the lead author Lu Wei, a Ph.D. candidate in chemistry.

Next, Min's team will apply this new technique to biomedical questions, such as detecting tumor cells and probing drug pharmacokinetics in animal models. They are also creating other alkyne-labeled biologically active molecules for more versatile imaging applications.

"Our new technique will open up numerous otherwise difficult studies on small biomolecules in live cells and animals," says Min. "In addition to basic research, our technique could also contribute greatly to translational applications. I believe SRS imaging of alkyne tags could do for small biomolecules what fluorescence imaging of fluorophores such as GFP has done for larger species."


Story Source:

The above story is based on materials provided by Columbia University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Lu Wei, Fanghao Hu, Yihui Shen, Zhixing Chen, Yong Yu, Chih-Chun Lin, Meng C Wang, Wei Min. Live-cell imaging of alkyne-tagged small biomolecules by stimulated Raman scattering. Nature Methods, 2014; DOI: 10.1038/nmeth.2878

Cite This Page:

Columbia University. "Imaging dynamics of small biomolecules inside live cells." ScienceDaily. ScienceDaily, 2 March 2014. <www.sciencedaily.com/releases/2014/03/140302143630.htm>.
Columbia University. (2014, March 2). Imaging dynamics of small biomolecules inside live cells. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2014/03/140302143630.htm
Columbia University. "Imaging dynamics of small biomolecules inside live cells." ScienceDaily. www.sciencedaily.com/releases/2014/03/140302143630.htm (accessed September 1, 2014).

Share This




More Matter & Energy News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: India Coal Strained by Supreme Court Ruling

Breakingviews: India Coal Strained by Supreme Court Ruling

Reuters - Business Video Online (Aug. 26, 2014) An acute coal shortage is likely to be aggravated as India's supreme court declared government coal allocations illegal, says Breakingviews' Peter Thal Larsen. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins