Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fluorescent nanoparticles serve as flashlights in living cells

09.05.2007
Scientists from the University of Twente, The Netherlands, have successfully exploited the optical properties of fluorescent nanoparticles to broaden the scope of single-cell microscopy. By using nanoparticles, they succeeded in combining two different optical microscopy techniques on the same cell. This opens exciting new possibilities for cellular imaging. Henk-Jan van Manen and Cees Otto from the Biophysical Engineering Group of the MESA+ Institute for Nanotechnology describe their results in Nano Letters.

The ‘quantum dot’ nanoparticles used by Van Manen and Otto replace existing fluorescent labels that are employed to enable the cell’s biomolecules to light up under the microscope. While fluorescence microscopy continues to be instrumental in unraveling the intricate biological processes that take place inside living cells, it would be even more informative to combine it with the intracellular chemical analysis capabilities of vibrational spectroscopy techniques such as Raman microscopy.

Common fluorescent labels are not suitable for this combination, however, because the much stronger fluorescence overshadows the intrinsic weak Raman signals coming from cells. By taking fluorescent quantum dots that emit light in a wavelength region that is well-separated from Raman signals, the Dutch researchers now show that fluorescence microscopy can indeed be combined with Raman microscopy on the same cell.

Vibrations inside cells

Techniques based on vibrational spectroscopy are able to detect the specific vibrations that occur inside the cell’s biomolecules (such as DNA, proteins, and lipids), making them very powerful tools for ‘chemical fingerprinting’ of cells. In contrast to fluorescence microscopy, vibrational spectroscopy does not require the biomolecules of interest to be labeled, which is a great advantage. The Biophysical Engineering Group at the University of Twente, headed by prof. Vinod Subramaniam, has pioneered the application of Raman spectroscopy to investigate the chemical make-up of single cells, and this group is now worldwide at the front of high-resolution chemical mapping of cells by Raman microscopy.

In their Nano Letters article, the researchers demonstrate two applications of the hybrid fluorescence Raman technique. By illuminating white blood cells with UV light at a wavelength of 413 nm, the Raman signal from an enzyme that is critical in the innate immune response can be detected and visualized across the cell. The fluorescence signal of quantum dot nanoparticles that have been ingested by the cells can be visualized separately. The second application employs light at a wavelength of 647 nm, which results in the separate detection of Raman signals from cellular proteins and lipids and the fluorescence signal from the nanoparticles.

Van Manen and Otto expect that the fluorescence Raman microscopy combination will provide exciting new possibilities: the nanoparticles might be coated on their surface with antibodies against, for example, marker proteins for cancer cells. In this way the quantum dots will serve as a torch for specific cells, which can subsequently be subjected to a detailed chemical analysis by using Raman microscopy.

The research described in the Nano Letters article was funded by the Landsteiner Foundation for Blood Transfusion Research (Amsterdam, The Netherlands) and the MESA+ Institute for Nanotechnology at the University of Twente.

Wiebe van der Veen | alfa
Further information:
http://bpe.tnw.utwente.nl/

Further reports about: Nano Raman fluorescence fluorescent nanoparticles spectroscopy

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>