Secondary tier assays like Pig-a offer significant value both for understanding a compound’s mode of action and for following up on a positive in vitro genetic toxicology assay.
Additional Support and Regulatory Follow-Up
- This assay is used for scoring the frequency of mutant phenotype erythrocytes (RBCs) and mutant phenotype immature erythrocytes (reticulocytes, or RETs) by measuring the induction of mutations at the Pig-a gene.
- Mutations in the Pig-a gene can prevent production of glycosylphosphatidylinositol (GPI) anchor proteins on the cell surface. Thus, cells without these cell surface markers represent a reliable phenotypic marker of Pig-a mutation.
- Easily integrates into standard toxicity studies
- Provides fast, quantifiable results via flow cytometry
- Uses very low volumes of blood
- 3Rs compliant
- Replaces transgenic rodent mutation assays
When to Perform
- IND-enabling studies
- To determine mutagenic potential
- Additional support
- To assess mutagenicity potential when the Ames assay is not appropriate (e.g., test item is toxic to bacteria)
- Follow-up on a positive result in the Ames assay
- Additional information for compounds with predicted mutagenic properties