In Vivo Rat Micronucleus Test

According to OECD Guidelines for Testing of Chemicals, Test No. 474, the in vivo rat micronucleus test is used to evaluate the presence of micronuclei containing lagging chromosome fragments or whole chromosomes in erythrocytes.

STEMart provides in vivo rat micronucleus test to detect the potential cytogenetic damage induced by a medical device to the chromosomes or the mitotic apparatus of erythroblasts. This assay is available under either GLP (Good Laboratory Practice) or Non-GLP conditions.

Standard

OECD 474

Test Model

Rat

Test Method

Rats in treatment group (include 5 animals per sex) are treated to at least three dose level of the medical device extract once, or twice at an interval of not more than 24 hours.

Fig. 1 Bone marrow micronucleus test. (Bowen, Damian E., 2011)

Samples of bone marrow are taken from the femurs or tibias at least twice between 24 and 48 hours after the last dose, with appropriate interval(s) between samples. Samples of peripheral blood are taken from the tail vein or other appropriate blood vessel at least twice between 36 and 72 hours after the last treatment, with appropriate interval(s) between samples.

Cells are then prepared and stained with Giemsa, fluorescent DNA specific dyes or other methods. The incidence of micronuclei is evaluated under microscopy in at least 2000 immature erythrocytes from each animal.

Image analysis and cell suspensions flow cytometry can be used for cell analysis.

Negative vehicle control and positive controls are included in each study.

Criteria

• Positive result: A dose-related increase and a statistically significant increase in the number of micronucleated polychromatic erythrocytes (MN-PCEs) or micronucleated reticulocytes (MN-RETs) in a single dose group at a single sampling time over that of the solvent controls.
• Negative result: No statistically significant increase in the number of cells with micronuclei.

Final Report

The final report including information on the methodology, raw data, analysis, and interpretation of the results will be provided for customer.

Advantages

• Automated scoring is available with image analysis and cell suspensions flow cytometry.

If you have additional questions about in vivo rat micronucleus test, or would like to find out more about our services, please feel free to contact us.

Reference

• US Food and Drug Administration. "Red Book 2000, Toxicological Principles for the Safety of Food Ingredients: IV. C. 1. d. Mammalian Erythrocyte Micronucleus Test." (2000).
• Bowen, Damian E., et al. "Evaluation of a multi-endpoint assay in rats, combining the bone-marrow micronucleus test, the Comet assay and the flow-cytometric peripheral blood micronucleus test." Mutation Research/Genetic Toxicology and Environmental Mutagenesis 722.1: 7-19 (2011).
• OECD Guideline for Testing of Chemicals. No 474 Mammalian Erythrocyte Micronucleus Test (1997).