Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Taking screening methods to the next level

17.10.2017

CRISPR-UMI, a novel method developed at IMBA, facilitates extremely robust and sensitive screens by tracking single mutants within a population of cells.

“The whole is greater than the sum of its parts” is an adage that applies to many concepts in biology. For genetic screens, however, it is the individual parts, i.e. the individual cells, that are the focus of the next generation of CRISPR-Cas9 screens. Single mutants within a population reveal new findings that could revolutionise target discovery and offer fresh insights into the biological systems of cell differentiation and cancer.


CRISPR-UMI relies on the addition of a high complexity barcoding system – or Unique Molecular Identifier (UMI) – that marks each single mutant clone and allows its tracking within a population.

(c)Philipp Zaufel, maximcapra.com

In recent years, different labs have been working on improving CRISPR screening technology by optimising guide efficiency, on-target specifity and Cas9 variants. But so far, no one has been able to address the concern of cellular heterogeneity, which affects the precision of screening results. The Elling Lab has now overcome this limitation.

As reported in the current issue of Nature Methods, the lab developed a new screening paradigm that allows scientists to track individual mutant cells within a screen. This breakthrough enables the detection of outliers within populations that would otherwise lead to incorrect conclusions and moreover can focus on the fraction of cells displaying a phenotype presumably due to homozygous mutation of genes by CRISPR/Cas9.

It also allows to quantify the phenotype independent on the technological aspect of how efficient knockout cells are generated. The innovative method relies on the addition of a high complexity barcoding system – or Unique Molecular Identifier (UMI) – that uniquely marks each mutant clone within a population.

“Instead of examining a pool of cells with variable genetic status, we can now look at hundreds of independent single cells derived clones separately. This method made it possible to reliable ascertain new drug targets for cancer therapy”, said Georg Michlits, first author.

Biological events with low probability, such as reprogramming a fibroblast to a stem cell or the formation of metastasis, can be considered to be stochastic events. A conventional screen is sensitive to the size of the event (large stem cell colony or large metastasis), but fails to assess the probability (regulation) of the event itself that is reflected in number versus size. Using CRISPR-UMI, Elling’s lab screened for genes that inhibit the reprogramming of differentiated cells to pluripotency.

“We were able to directly quantify the number and size of independent iPS cell colonies that appeared in the screen, revealing whether the selected genes regulate speed or likelihood of the switch to pluripotency. CRISPR-UMI therefore enabled a direct biological interpretation of screening results”, said Ulrich Elling, group leader at IMBA.

Original Publication: Michlits et al., 'CRISPR-UMI: single-cell lineage tracing of pooled CRISPR–Cas9 screens', Nature Methods, 2017, doi.10.1038/nmeth.4466

About IMBA
IMBA - Institute of Molecular Biotechnology is one of the leading biomedical research institutes in Europe focusing on cutting-edge functional genomics and stem cell technologies. IMBA is located at the Vienna Biocenter, the vibrant cluster of universities, research institutes and biotech companies in Austria. IMBA is a basic research institute of the Austrian Academy of Sciences, the leading national sponsor of non-university academic research. www.imba.oeaw.ac.at

About the Vienna BioCenter
The Vienna BioCenter (VBC) is a leading life sciences location in Europe, offering an extraordinary combination of research, education and business on a single campus. About 1,700 employees, more than 1,300 students, 88 research groups, 18 biotech companies, and scientists from more than 69 nations create a highly dynamic environment. This research was part of the VBC PhD Programme. www.viennabiocenter.org

Weitere Informationen:

http://www.imba.oeaw.ac.at/research-highlights/taking-screening-methods-to-the-n...

Mag. Evelyn Devuyst | idw - Informationsdienst Wissenschaft

More articles from Life Sciences:

nachricht Stiffness matters
22.02.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Separate brain systems cooperate during learning, study finds
22.02.2018 | Brown University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Stiffness matters

22.02.2018 | Life Sciences

Magnetic field traces gas and dust swirling around supermassive black hole

22.02.2018 | Physics and Astronomy

First evidence of surprising ocean warming around Galápagos corals

22.02.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>