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Posted by ivocabral on

Video – Comet assay, step by step

The Norwegian Institute for Air Research (NILU), coordinator of RiskGONE, created a short video showing the main steps in conducting a comet assay, in order to assess the toxicity of nanomaterials.

One of the aims of the RiskGONE project is the verification, optimisation and development of methods for the characterization and human and eco-toxicological hazard assessment of ENMs (engineered nanomaterials). This is done through interlaboratory round robin exercises and training on selected methods. One of these methods is the Comet assay (single cell gel electrophoresis), a simple method used for measuring DNA damage in eukaryotic cells. The method is widely used for detection of strand breaks as well as specific DNA lesions, such as oxidized purines and pyrimidines, and is considered a useful method for genotoxicity testing in vitro as well as in vivo.

NILU provided RiskGONE partners with training on this method at a course that took place in February 2020, and in March 2021, through a practical online course/video learning due to the COVID-related restrictions. The video available below is part of the training material used in this course.

How the Comet Assay works

After exposure to the compound of interest (in this case, ENM), the cells are embedded in agarose on a microscope slide. After treatment with a detergent solution, membranes, cytoplasm, and most of the soluble cell contents are dissolved, and the DNA nucleoids are freed. The nucleoids are then subjected to an electrophoretic field, which makes the negatively charged DNA migrate towards the positive electrode-anode. DNA in the nucleoids is very compact and its movement is limited, but if a break is present in the DNA strands, the DNA loop is free to extend under the electrophoretic field and move towards the anode. When DNA is stained with specific dyes and examined microscopically, images resembling comets are seen; the comet tail consists of loops of DNA that, due to the presence of damage (strand break), have moved out from the nucleoid (comet head). The amount of DNA in the tail reflects the number of breaks in the DNA.

The standard comet assay measures single- and double-strand breaks. A modified version of the assay by inclusion of lesion-specific enzymes can detect specific DNA lesions, such as oxidized purines using formamidopyrimidine DNA glycosylase (Fpg).

Posted by ivocabral on

Webinar recording: identifying health hazards with AOPs – watch it anytime!

Webinar recording: identifying health hazards with AOPs – watch it anytime!

On 5th June, RiskGONE held its second webinar, attended by more than 40 participants. This time project partners focused the discussion on how to use Adverse Outcome Pathways (AOPs), a risk-assessment method, to analyse the possible hazards nanomaterials can pose to human health.

Experts from KU Leuven (Belgium), the Institute for Medical Research and Occupational Health (Croatia) and the QSAR lab (Poland) explained how they are applying this method to tracing nanomaterials risks.

AOPs could help researchers find negative effects from nanomaterials more efficiently, and reduce the need for animal testing. So, how do AOPs work in practice? The idea behind is that researchers create pathways that link a first event observable at molecular level with subsequent effects in the human body and the final problems they can pose to human health, which can be as serious as cancer, neurodegeneration or decreased fertility.

These pathways are living documents that can be accessed online through the AOP Wiki website and be modified as fresh evidence reveals new or different effects of nanomaterials in human health. The AOPs system is a tool launched by the OECD in 2012 to systematically assess toxicological risks in chemicals. Researchers in the RiskGONE project propose using these AOPs to map possible hazards in using nanomaterials too.

Eager to know more? We have recorded the webinar for you! Simply click on the links below to watch the webinar sections of your interest:


Access all the presentation slides from speakers here. 

Posted by piamarina on

Webinar on nanotechnology risk-assessment method AOP – register now!

Webinar on nanotechnology risk-assessment method AOP – register now!

Nanotechnologies have useful applications, but do present risks, such as toxicity or flammability under some conditions. The RiskGONE project is researching on how to assess hazards using Adverse Outcome Pathways (AOPs), a risk-assessment method used to analyse how biological events may lead to adverse effects.

Using AOPs is common for assessing hazards posed by chemicals, but not yet for nanomaterials. Therefore, RiskGONE researchers work to adapt this kind of methods to be used in testing risks in new nano-based technologies.

Are you a nanomaterial student, or an engineer? Just interested in these developments? RiskGONE experts are holding a webinar on 5 June at 12.30pm (Brussels Time). They will go in detail on how to use AOPs to assess risks in new nanotechnology applications.

On the programme:

  • Introduction of the AOP together with brief description of OECD-sponsored AOP Knowledge base (AOP-KB), by Dr. Ivana Vinković Vrček, Analytical Toxicology and Mineral Metabolism Unit, Institute for Medical Research and Occupational Health, Zagreb (Croatia).
  • Overview of a systematic literature search summarizing existing AOPs for nanomaterials, as performed in riskGONE project and examples on how to generate a testable hypothesis for AO of nanomaterials from chemical AOPs, by Prof. Peter Hoet and Mr. Sivakumar Murugadoss, Laboratory of Toxicology, Department of Public Health and Primary Care, KU Leuven (Belgium).
  • Introduction and discussion over the concept of quantitative structure activity relationship (QSAR), by Dr. Karolina Jagiello, QSAR lab, Gdańsk (Poland)
  • Open discussion

Registrations are open to everyone! To attend, just fill in this form.


Posted by piamarina on

Webinar recording – your chance to catch up anytime!

Webinar recording – your chance to catch up anytime!

Our first webinar brought together the expertise of leading RiskGONE project partners in order to explain how we go about our mission to improve risk governance of engineered nanomaterials and how interested stakeholders can get involved.

We have recorded the webinar for you so that you can get back to it anytime. Simply click on the links below to watch the webinar sections of your interest!

Posted by nils.bohmer on

Register for our webinar: RiskGONE Project – Governance of Nanomaterials in the EU

Register for our webinar: RiskGONE Project – Governance of Nanomaterials in the EU

Be part of our 1st webinar and find out more about RiskGONE!
Partners leading on different activities of RiskGONE will talk about the project itself, its visions and ambitions as well as about the possibilities for YOU to interact with us and actively influence the future governance of nanomaterials in the EU and worldwide!

Time and Date:
Round 1 – 19 March 2020, 12.30-13:15 CET
Round 2 – 30 March 2020, 15.00-15:45 CET

Registration (free of charge):


  • Welcome (Michael Neaves, ECOS)
  • The RiskGONE Project (Eleonora Longhin, NILU)
    • Project Background
    • Aims and Objectives
    • NMBP-13 Cooperation
  • RiskGONEs approach towards a Risk Governance Council and Framework (Panagiotis Isigonis, UNIVE)
  • Risk Assessment and Decision-making Tools (Tomasso Serchi, LIST)
  • Q&A
  • Getting involved in RiskGone! (Michael Neaves, ECOS)