Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers develop new way to see single RNA molecules inside living cells

08.04.2009
Biomedical engineers have developed a new type of probe that allows them to visualize single ribonucleic acid (RNA) molecules within live cells more easily than existing methods. The tool will help scientists learn more about how RNA operates within living cells.

Techniques scientists currently use to image these transporters of genetic information within cells have several drawbacks, including the need for synthetic RNA or a large number of fluorescent molecules. The fluorescent probes developed at the Georgia Institute of Technology circumvent these issues.

"The probes we designed shine bright, are small and easy to assemble, bind rapidly to their targets, and can be imaged for hours. These characteristics make them a great choice for studying the movement and location of RNA inside a single cell and the interaction between RNA and binding proteins," said Philip Santangelo, an assistant professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.

Details of the probe production process and RNA imaging strategy were published online in the journal Nature Methods on April 6. In addition to Santangelo, Georgia Tech graduate student Aaron Lifland, Emory University associate professor Gary Bassell and Vanderbilt University professor James Crowe Jr. also contributed to this research. This research was funded by new faculty support from Georgia Tech.

In the study, the probes – produced by attaching a few small fluorescent molecules called fluorophores to a modified nucleic acid sequence and combining the sequences with a protein – exhibited single-molecule sensitivity and allowed the researchers to target and follow native RNA and non-engineered viral RNA in living cells.

"The great thing about these probes is that they recognize RNA sequences and bind to them using the same base pairing most people are familiar with in regards to DNA," explained Santangelo. "By adding only a few probes that would bind to a region of RNA, we gained the ability to distinguish a targeted RNA molecule from a single unbound probe because the former lit up two or three times brighter."

For their experiments, the team used a bacterial toxin to transport the probes into living cells – a delivery technique that when combined with the high affinity of the probes for their targets, required significantly fewer probes than existing techniques. The toxin created several tiny holes in the cell membrane that allowed the probes to enter the cell's cytoplasm.

The researchers tested the sensitivity of conventional fluorescence microscopy to image individual probes inside a cell. Previous studies showed that these techniques were able to image an accumulation of probes inside a cell, but the current study demonstrated that individual probes without cellular targets could be observed homogenously distributed in the cytoplasm with no localization or aggregation.

With single-molecule sensitivity accomplished, the researchers investigated whether they could visualize individual RNA molecules using the probes. To do this, they simultaneously delivered probes designed to target a human messenger RNA (mRNA) sequence region and a probe designed with no target in the human genome. They were able to image unbound probes of both types as well as individual RNA molecules that had attached to the former probes.

The imaging technique also allowed the researchers to observe a process called dynamic RNA-protein co-localization, which is the joining of RNA molecules and RNA binding proteins in a single cell.

"We observed substantial transient interactions between proteins and viral RNA molecules that I don't think had ever been seen before with non-engineered RNA," noted Santangelo. "We saw one of the proteins move into a viral RNA granule and reside within it for over a minute before it was released, and we also saw another protein that appeared to dock with a viral RNA granule."

Santangelo is currently trying to improve the probes by making them smaller and brighter, while also using them to investigate viral pathogenesis and other biological phenomena.

"We are excited to use this imaging strategy to study how single viral RNAs travel from the nucleus of a cell to a virus assembly site, how mRNAs are regulated by location and time, and RNA trafficking in neurons," added Santangelo.

Abby Vogel | EurekAlert!
Further information:
http://www.gatech.edu

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>