Tradescantia micronucleus bioassay

Area of Science:

• Environmental Science
• Toxicology
• Genetics

Background:

• The International Programme on Chemical Safety coordinated a study to assess plant bioassays.
• The Tradescantia micronucleus (Trad-MCN) assay is a plant-based bioassay used for genotoxicity testing.

Purpose of the Study:

• To evaluate the sensitivity, efficiency, and reliability of the Trad-MCN bioassay.
• To assess the Trad-MCN assay's performance in an international collaborative study.

Main Methods:

• Four coded chemicals (azidoglycerol, N-methyl-N-nitrosourea, sodium azide, maleic hydrazide) were tested.
• Five independent laboratories followed a standard Trad-MCN protocol with three replicate tests per chemical.

Main Results:

• All laboratories reported positive results for maleic hydrazide and N-methyl-N-nitrosourea.
• Four of five laboratories found sodium azide to be positive.
• Azidoglycerol yielded mixed results, with one lab reporting positive results only at a high dose.

Conclusions:

• The Trad-MCN bioassay is an efficient and reliable short-term assay for clastogens under normal conditions.
• The assay is suitable for rapid chemical screening and in situ monitoring of ambient pollutants.