# CometChip: Development of a high throughput DNA damage assay in hepatocytes

> **NIH NIH U44** · INTEGRATED LABORATORY SYSTEMS, LLC · 2020 · $799,905

## Abstract

An estimated 10,000 animals are used in toxicology safety assessments to meet all regulatory
requirements with testing spanning 5 to 10 yrs and exceeding $10 million dollars. There is a critical
need to reduce reliance on animal testing and to develop highly predictive human-based biological
models for safety assessments. Replacement of traditional animal toxicity tests for toxicology
safety assessments with alternative tests requires rigorous validations for acceptance of an
alternative method by regulatory agencies. The genetic toxicology test battery required by
regulatory agencies worldwide, directly measures DNA damage, gene mutation, chromosomal
damage in cell culture and in animals. The in vivo Comet assay in rodent liver is a component of
the required genetic toxicology test battery that detects a broad range of DNA lesions and is
considered a powerful tool to distinguish between genotoxic carcinogens and nongenotoxic
carcinogens. This regulatory assay is expensive, inefficient and can require up to 45 animals for
each test compound. We developed a medium throughput Comet assay platform (CometChip®)
using a human liver cell line HepaRG™ that maintains active, inducible spectrum of CYP450s
and Phase II enzyme cells. We have qualified this assay by testing more than 60 compounds at
Integrated Laboratory systems and MIT for use in the assessment of DNA damage and are now
able to conduct interlaboratory trials to validate this assay as a non-animal alternative to the in
vivo Comet assay. This SBIR 2B is directed at validating CometChip® technology to detect
DNA damage using metabolically competent HepaRG™ cells and hepatocytes as an in
vitro alternative to the in vivo Comet assay. This will be accomplished in four Specific Aims:
Aim 1 Conduct literature review and build database of in vivo Comet assay responses for
publication in peer-reviewed literature; Aim 2 Finalize HepaRG™ CometChip® assay specific
SOPs, quality control criteria, validation of instrumentation and GLP-compliant protocols; Specific
Aim 3 Conduct HepaRG™ CometChip® assay on 100-150 compounds per year for 3 years based
on biological activity from Tox 21; Specific Aim 4 Develop Master Validation Plan and Execute
Interlaboratory Validation; The specific purpose of this SBIR 2B application and Master Validation
Plan is to develop an in vitro alternative to the in vivo Comet assay (OECD 489) used by regulators
worldwide for the assessment of genotoxicity in liver. This SBIR 2B application is aimed validating
and translating an innovative test method developed through multiple NIH SBIR Phase II
programs as an alternative to required animals testing that will better predict how chemicals may
affect humans and the environment and reduce reliance on animals.

## Key facts

- **NIH application ID:** 9966994
- **Project number:** 5U44ES024698-06
- **Recipient organization:** INTEGRATED LABORATORY SYSTEMS, LLC
- **Principal Investigator:** Bevin P. Engelward
- **Activity code:** U44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $799,905
- **Award type:** 5
- **Project period:** 2014-08-19 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9966994

## Citation

> US National Institutes of Health, RePORTER application 9966994, CometChip: Development of a high throughput DNA damage assay in hepatocytes (5U44ES024698-06). Retrieved via AI Analytics 2026-06-08 from https://api.ai-analytics.org/grant/nih/9966994. Licensed CC0.

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