Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bright lights for live cells

26.07.2010
Surface-selective fluorescent labeling enables cell tracking in the body while preserving initial cell function

Chemical reactions that create durable bonds between cells and fluorescent dyes are an attractive way to monitor biological functions in the body. However, they can also detrimentally modify key chemical groups on cell surfaces.

Chemically binding fluorescent dyes to cells—with minimal impact on their original function—is now possible, thanks to a site-selective reaction developed by a team led by Yasuyoshi Watanabe and Tsuyoshi Tahara from the RIKEN Center for Molecular Imaging Science, Kobe¹.

Working closely with Katsunori Tanaka and Koichi Fukase from Osaka University, the researchers decided to use organic compounds called aldehydes as dye precursors as they readily react with nitrogen-containing functionalities, or amino groups, exposed at protein surfaces.

To assess the efficacy of their method, the team mixed the aldehydes with brain cancer cells in vitro for 10 minutes then compared them with typical amino reactive dye precursors known as succinimidyl esters (NHS) (Fig. 1). They discovered that the aldehyde precursors produced brighter fluorescence than the NHS dyes.

Confocal microscopy showed that the aldehydes reacted with amino groups of lysine amino acid residues on the cell surface and those of other cell membrane components, whereas the NHS dyes penetrated the cells. They confirmed this by treating the labeled cells with detergent: the aldehyde-derived labels washed off the cell surface, whereas their NHS counterparts remained in the cells. The aldehyde-derived labels also remained effective at exceptionally low concentrations, unlike the NHS-derived labels.

“In contrast to pre-existing cell labeling protocols, this reaction tightly anchors the labels to the surface of living cells within 10 minutes at 10 nM [dye] concentrations and with a very simple ‘kit-like’ operation,” say Watanabe and Tahara. The team also observed that the brain cells maintained their ability to undergo cell division after labeling because of the mild reaction conditions.

The researchers also labeled lymphocytes, extracted from mice, with the fluorescent dyes and injected them into live mice for in vivo monitoring. They found that the labels clearly highlighted the trafficking of the cells into the organs of the mouse immune system. In particular, they noted that the cells gradually accumulated in the spleen and intestinal lymph nodes in six hours before disappearing from the spleen.

In addition to investigating potential clinical applications, the team is currently planning to apply their method to the synthesis of metal binding labels to introduce radioactive and magnetic properties into cells for imaging techniques such as positron emission tomography and magnetic resonance imaging.

The corresponding author for this highlight is based at the Molecular Probe Dynamics Laboratory, RIKEN Center for Molecular

Journal information
1. Tanaka, K., Minami, K., Tahara, T., Fujii, Y., Siwu, E.R.O, Nozaki, S., Hirotaka, O., Yokoi, S., Koyama, K., Watanabe, Y. & Fukase, K. Electrocyclization-based labeling allows efficient in vivo imaging of cellular trafficking. ChemMedChem 5, 841–845 (2010).

gro-pr | Research asia research news
Further information:
http://www.riken.jp
http://www.rikenresearch.riken.jp/eng/research/6340
http://www.researchsea.com

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 >>>