Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Novel quantum dots enhance cell imaging

30.10.2018

A team of researchers from the University of Illinois at Urbana-Champaign and Mayo Clinic have engineered a new type of molecular probe that can measure and count RNA in cells and tissue without organic dyes. The probe is based on the conventional fluorescence in situ hybridization (FISH) technique, but it relies on compact quantum dots to illuminate molecules and diseased cells rather than fluorescent dyes.

Over the last 50 years, FISH has evolved into a multi-billion-dollar industry because it effectively images and counts DNA and RNA in single cells. However, FISH has its limitations due to the delicate nature of the dyes. For example, the dyes rapidly deteriorate and are not very good at imaging in three dimensions. In addition, conventional FISH can only read out a couple of RNA or DNA sequences at a time.


Quantum dots illuminate the locations of individual mRNA as red dots in the cytoplasm of a single HeLa cell. The blue region is the nucleus. This work was a collaborative effort between Illinois Bioengineering and Mayo Clinic researchers.

Credit: University of Illinois at Urbana-Champaign Department of Bioengineering

Quantum dots illuminate the locations of individual mRNA as red dots in the cytoplasm of a single HeLa cell. The blue region is the nucleus. This work was a collaborative effort between Illinois Bioengineering and Mayo Clinic researchers.

Quantum dots illuminate the locations of individual mRNA as red dots in the cytoplasm of a single HeLa cell. The blue region is the nucleus. This work was a collaborative effort between Illinois Bioengineering and Mayo Clinic researchers.

"By replacing dyes with quantum dots, there are no stability issues whatsoever and we can count numerous RNAs with higher fidelity than before," said Andrew Smith, an associate professor of Bioengineering and member of the research team. "Moreover, we uncovered a fundamental limit to the size of a molecular label in cells, revealing new design rules for analysis in cells."

In their latest paper, published October 26, 2018, in the online edition of Nature Communications, Smith and his team identified an optimal size for quantum dots in order to effectively work with the FISH protocol. This discovery enabled quantum dot-based FISH to match the labeling accuracies currently obtained with organic dyes.

The team created unique quantum dots that are made of a zinc, selenium, cadmium, and mercury alloy and are coated with polymers. "The core of the dot dictates the wavelength of emission, and the shell dictates how much light will be given off," said Smith, who is also affiliated with the Micro + Nanotechnology Lab, Carle Illinois College of Medicine, and Department of Materials Science and Engineering at the University of Illinois.

These dots can emit color independent of the size of the particle, which is not the case for conventional quantum dots. The dots are also small enough (7 nanometers) to fit on a probe that can maneuver between proteins and DNA in a cell, making them more comparable in size to the dyes used in conventional FISH probes.

In experiments with HeLa cells and prostate cancer cells, the researchers found that dye-based FISH cell counts declined rapidly in minutes. The quantum dot-based FISH method provided long-term luminescence to allow counting of RNA for more than 10 minutes, making it possible to acquire 3D cell imaging.

"This is important because images of cells and tissues are acquired slice-by-slice in sequence, so later slices that are labeled with dyes are depleted before they can be imaged," said Smith.

###

This research is part of the Mayo Illinois Alliance in which engineers from Illinois work directly with clinicians and biologists from Mayo Clinic to solve outstanding medical challenges. The Mayo Clinic Biomarker Discovery Group is working to develop FISH-based diagnostics for tumor biopsies in order to improve the accuracy of cancer diagnosis, to select personalized treatments, and to improve prognoses. The QD-FISH methodology was developed to meet this need for biomarker panels requiring the analysis of numerous genetic changes in cells in tumors for which only small amounts of specimens may be available when acquired with a fine needle, as is often the case in prostate cancer.

This research was funded by the Mayo-Illinois Alliance, National Institutes of Health, and the National Science Foundation. The full title of the paper is "Enhanced mRNA FISH with Compact Quantum Dots."

In addition to Smith, the following Illinois Bioengineering researchers contributed to the work: Yang Liu, Phuong Le, Sung Jun Lim, Liang Ma, and Suresh Sarkar. Mayo Clinic collaborators include: Dr. Farhad Kosari, Stephen Murphy, John Cheville, and George Vasmatzis.

Andrew Smith | EurekAlert!
Further information:
https://bioengineering.illinois.edu/news/article/28774
http://dx.doi.org/10.1038/s41467-018-06740-x

Further reports about: Bioengineering DNA HeLa QUANTUM RNA cytoplasm mRNA prostate cancer quantum dots

More articles from Health and Medicine:

nachricht Purdue cancer identity technology makes it easier to find a tumor's 'address'
16.11.2018 | Purdue University

nachricht Microgel powder fights infection and helps wounds heal
14.11.2018 | Michigan Technological University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

 
Latest News

Controlling organ growth with light

19.11.2018 | Life Sciences

New way to look at cell membranes could change the way we study disease

19.11.2018 | Life Sciences

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

VideoLinks
Science & Research
Overview of more VideoLinks >>>