Simplified mouse peripheral reticulocyte micronucleus test with dimethylnitrosamine

Area of Science:

• Toxicology
• Genetics

Background:

• The micronucleus test is a standard genotoxicity assay.
• Assessing genotoxicity in peripheral blood offers potential advantages over bone marrow sampling.

Purpose of the Study:

• To compare the efficacy and sensitivity of the micronucleus assay in peripheral blood versus bone marrow cells.
• To evaluate the use of acridine orange-coated slides for peripheral blood micronucleus detection.

Main Methods:

• Male CD-1 mice were treated with dimethylnitrosamine.
• Micronuclei were analyzed in bone marrow polychromatic erythrocytes and peripheral blood reticulocytes.
• Peripheral blood slides were prepared using acridine orange (AO)-coated slides and examined via fluorescence microscopy.

Main Results:

• A significant increase in micronuclei was observed in both bone marrow and peripheral blood cells post-treatment.
• The peak frequency of micronuclei in peripheral reticulocytes was observed 24-48 hours after treatment, approximately 24 hours later than in bone marrow.
• The peripheral blood micronucleus test demonstrated comparable sensitivity to the bone marrow assay.

Conclusions:

• The micronucleus assay using peripheral blood with AO-coated slides is a viable and sensitive alternative to the traditional bone marrow assay.
• This method is easier to perform and suitable for genotoxicity testing.