This protocol is provided for testing of nanomaterials (NM) with standard cell lines in the absence of metabolic activation.
In Vitro Micronucleus Assay: method for assessment of nanomaterials using Cytochalasin B.
Frontiers in Toxicology, 2023
The mission of this committee is to improve the scientific basis of the interpretation of results from genetic toxicology tests for purposes of more accurate hazard identification and assessment of human risk; to develop follow-up strategies for determining the relevance of test results to human health; to provide a framework for integration of testing results into a risk-based assessment of the effects of chemical exposures on human health; to promote the integration and use of new techniques and scientific knowledge in the evaluation of genetic toxicology; and to monitor and promote the development of innovative tests and testing strategies.
Launched in 2022, the Education and Science Outreach Working Group aims to promote genetic toxicology as a career path and equip the next generation of scientists with foundational skills and experiences. By creating opportunities for networking, skill-building, and mentorship, the group supports early-career researchers in advancing their expertise and connecting with leaders in the field.
Since 2024, the GTTC has offered two professional development awards that help trainees share their research and grow professionally.
All awardees are invited to the GTTC Annual Meeting to learn about emerging projects and science at HESI and to network with experts in the gene toxicology field.
Leadership Team:
Joel Bercu (Gilead)
HESI Staff:
Raechel Puglisi, MPH
This working group is focused on evaluating error corrected next generation sequencing (ECS) as an alternative method for assessing in vivo mutagenesis. It’s current focus is on investigating the suitability of ECS for regulatory mutagenicity testing. The working group is currently focused on:
Leadership Team:
Shaofei Zhang (Pfizer), Javier Revollo (US FDA/NCTR)
HESI Staff:
Connie Chen, PhD, MPH
This working group focuses on developing and refining protocols for assessing genotoxic effects on germ cells. Current efforts include:
Leadership Team:
Roger Godschalk (Maastricht University), Jan van Benthem, PhD (RIVM, Retired)
HESI Staff:
Connie Chen, PhD, MPH
This working group aims to critically evaluate new approach methodologies (NAMs) for in vitro genotoxicity testing, aiming to expand current testing strategies and ultimately make recommendations for creating an “in vitro only” approach for genetox testing that meets the needs of various regulatory decision-makers. The group is currently focused on the first of its committee-defined goals, which involves a comprehensive critical evaluation of NAMS through four focus areas:
Leadership Team:
Marc Beal (Merck & Co.), Giel Hendriks, PhD (Toxys B.V.)
Subteam Leadership: IVIVE – Alexandra Long (Health Canada); Metabolism – Nikolai Chepelev (Health Canada), Xiaoqing Guo (US FDA/NCTR); Indirect GTX – Ashley Allemang (P&G), Inger Brandsma (Toxys); Aneugens – Xiaowen Sun (Pfizer)
HESI Staff:
Alexandra Taraboletti, PhD
This working group is dedicated to offering detailed guidance and best practices for selecting and conducting in vivo tests following a positive genotoxicity result. A key focus is ensuring that follow-up testing aligns with regulatory requirements and scientific best practices. The current focus is on cytotoxicity of in vivo comet assays (data collection for retrospective analysis and development of a novel in vivo study). The recent pilot study data are under analysis, and on the following:
Leadership Team:
Carol Beevers (Corteva), Matt LeBaron (Dow Chemical Company), David Lovell (St. George’s University of London)
HESI Staff:
Connie Chen, PhD, MPH
The MRGA working group integrates the efforts of the former MOA and Clean Sheet working groups to establish a new mechanism-based paradigm for genotoxicity risk assessment. The group is composed of two subgroups focusing on Nitrosamines, and Titanium Dioxide (TiO2).
Nitrosamines Working Group
The primary objective of this subteam is to advance the scientific understanding and risk assessment of nitrosamines’ genotoxic potential through innovative mechanism-based testing approaches. (Leadership Team: Tetyana Cheairs (NY Medical College), Joel Bercu (Gilead))
This subteam has four working groups:
For more information about this subgroup – https://hesiglobal.org/gttc-nitrosamines/
o-NNO Working Group
This working group is focused on developing a science-based framework for evaluating the genotoxic and carcinogenic potential of n-nitroso compounds that are not nitrosamines (o-NNOs). The group will assess the current scientific data regarding genotoxicity and carcinogenicity of o-NNOs, identify data gaps, and generate experimental evidence and develop predictive models to inform quantitative risk assessment and safety limit setting
Leadership Team:
Michelle Kenyon (Pfizer)
HESI Staff:
Connie Chen, PhD, MPH
This working group is completing several OECD AOP wikis. The first AOP “Oxidative DNA damage leading to mutations and chromosomal damage” was published on the AOPWiki in April 2023. The tubulin binding and topoisomerase II inhibition AOPs will be completed in early 2024, after which this work group will merge into the new MGRA work group.
Leadership for Tubulin binding AOP:
Yasmin Dietz (Sanofi)
Leadership for Topoisomerase II AOP:
Xiaowen Sun (Pfizer), Ryan Wheeldon (J&J)
HESI Staff:
Connie Chen, PhD, MPH
This working group is driving advancements in genetic toxicology by evaluating chemical data and enhancing dose-response modeling tools. Key projects include:
Research highlights involve optimizing in vivo study designs for precise Benchmark Dose (BMD) calculations and assessing inter-individual DNA repair variability. These efforts aim to promote broader adoption of dose-response modeling in regulatory decision-making.
Leadership Team:
George Johnson (GTox Ltd.), Andreas Zeller (Roche), Paul White (Health Canada)
HESI Staff:
Alexandra Taraboletti, PhD

The HESI Global Genetic Toxicology Technical Committee (GTTC) Education and Science Outreach Committee is pleased to announce the recipients of the 2026 Professional Development Travel Awards.
These awards will provide opportunities for new investigators to attend scientific conferences, workshops, or courses, etc., to build core competencies and transferable skills, and/or share their research.
Two award categories:
• Professional Development Travel Award: Provides $1,500 USD for travel to attend scientific conferences or workshops.
• Professional Development Training Award: Provides $4,000 USD for travel specific to training courses, cross-lab trainings, etc., to build core competencies and transferrable skills.


2025 Travel Awardees: Alina Göpfert (BASF SE, Ludwigshafen / Free University Berlin), Caitlin Maggs (Swansea University), Deniz Akin (Swansea University), Gloria Melzi (University of Milan), Josie Jabbour (University of Ottawa), Sofija Stojanovic (University of Groningen, The Netherlands), Vanitha Thurairsu (National University of Malaysia)
2025 Training Awardees: Alina Göpfert (BASF SE, Ludwigshafen / Free University Berlin), Alper James Alcaraz (University of Ottawa)
2024 Travel Awardees: Elena Esina (University of Ottawa), Rim Nassar (University of Montpellier – France and Lebanese University), Madeleine Oman (University of Toronto), Lily Thompson (Thomas Jefferson University), Xinwen Zhang (NIEHS)
2024 Training Awardee: Caitlin Maggs (Swansea University)
2023 Awardees: Tony Okeke (Drexel University), Ammer Khawam (McGill University), Natalia Bertolez (University of Coruna), Sarah Park (Oak Ridge, US EPA), Victoria Bastos (Maastricht University), Alper Alcarez (NIEHS), Idoia Meaza Izusi (University of Louisville)
2022 Spring Awardees: Jonathan Axellson (UOttawa), Julie Sanders (Sciensano), Anouk Thienpont (VUB), Sam Vielee (U Louisville), David Schuster (UOttawa), Danila Cuomo (Texas A&M).
2022 Fall Awardees: Zhenming Yang (Rutgers), Lee Pribyl (MIT), Natalie Laspata (Pittsburg), Daniela Muoio (Pittsburg), Elizabeth Irvin (NC State), Rebekah Petroff (Michigan).
Corteva Agriscience
Health Canada
No results.
Frontiers in Toxicology, 2023
This protocol is provided for testing of nanomaterials (NM) with standard cell lines in the absence of metabolic activation.
Frontiers in Toxicology, Nanotoxicology, 2022
The in vivo Comet assay measures the generation of DNA strand breaks under conditions in which the DNA will unwind and migrate to the anode in an electrophoresis assay, producing comet-like figures. Measurements are on single cells, which allows the sampling of a diversity of cells and tissues for DNA damaging effects. The Comet ...
Mutagenesis, 2016
Applied genetic toxicology is undergoing a transition from qualitative hazard identification to quantitative dose–response analysis and risk assessment. To facilitate this change, the Health and Environmental Sciences Institute (HESI) Genetic Toxicology Technical Committee (GTTC) sponsored a workshop held in ...
Environmental and Molecular Mutagenesis, 2011
The Health and Environmental Sciences Institute (HESI), a global branch of the International Life Sciences Institute (ILSI), initiated a project committee entitled “Relevance and Follow-up of Positive Results from In Vitro Genetic Toxicity Testing (IVGT)” with the overall objective of improving the scientific basis for ...
Environmental and Molecular Mutagenesis, 2011
The International Life Sciences Institute (ILSI) Health and Environmental Sciences Institute (HESI) Project Committee on the Relevance and Follow-up of Positive Results in In Vitro Genetic Toxicity (IVGT) Testing established an Emerging Technologies and New Strategies Workgroup to review the current State of the Art in ...
Environmental and Molecular Mutagenesis, 2016
To enable the broader context for examining genetic damage, a next generation testing strategy needs to take into account a broader, more flexible approach to testing, and ultimately modeling, of genomic damage as it relates to human exposure. The outline of a flexible ...
The Genetic Toxicology Technical Committee (GTTC) is part of the Center for Translational Sciences. This HESI Center serves as a focal point for staff to share strategic approaches, scientific developments, management best practices and innovations with other related HESI committees.
Other Committees in the Center for Translational Sciences are:
For questions about the Center contact:
hesi@hesiglobal.org
Phone: +1-202-659-8404
Fax: +1-202-659-8403
740 15th Street NW, Suite 600
Washington, DC 20005
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