Evaluation of high-throughput screening for in vitro micronucleus test using fluorescence-based cell imaging

Area of Science:

• Toxicology
• Genetics

Background:

• The in vitro micronucleus (MN) test is a key genotoxicity screening tool, often replacing the in vitro chromosome aberration (CA) test due to its simplicity.
• The MN assay's practicality makes it suitable for high-throughput screening (HTS) applications in chemical safety assessments.

Purpose of the Study:

• To validate the in vitro micronucleus (MN) test using a confocal imaging plate reader (IN Cell Analyzer 1000) for genotoxicity screening.
• To assess the efficiency and accuracy of an automated HTS assay for MN detection.

Main Methods:

• A validation study was conducted using 30 chemicals, including clastogens and aneugens.
• Chinese hamster lung cells (CHL/IU) in 96-well microplates were stained and analyzed using the IN Cell Analyzer 1000 for automated MN identification and counting.
• Automated image analysis was employed for MN detection and quantification.

Main Results:

• The automated MN test results showed high consistency with established in vitro MN and CA test reference data.
• The IN Cell Analyzer 1000 system accurately identified and counted micronuclei in treated cells.
• The HTS assay demonstrated reliable performance across 30 diverse chemical agents.

Conclusions:

• The validated automated in vitro micronucleus test provides an efficient and accurate method for genotoxicity screening.
• This HTS assay is suitable for early-stage chemical development, enabling rapid safety assessments.
• Automated image analysis significantly enhances the practicality and throughput of the MN assay.