Recommendations for conducting the rodent erythrocyte Pig-a assay: A report from the HESI GTTC Pig-a Workgroup

Environ Mol Mutagen. 2021 Mar;62(3):227-237. doi: 10.1002/em.22427. Epub 2021 Mar 2.


The rodent Pig-a assay is a flow cytometric, phenotype-based method used to measure in vivo somatic cell mutation. An Organization for Economic Co-operation and Development (OECD) test guideline is currently being developed to support routine use of the assay for regulatory purposes (OECD project number 4.93). This article provides advice on best practices for designing and conducting rodent Pig-a studies in support of evaluating test substance safety, with a focus on the rat model. Various aspects of assay conduct, including laboratory proficiency, minimum number of animals per dose group, preferred treatment and blood sampling schedule, and statistical analysis are described.

Keywords: Pig-a gene; flow cytometry; genotoxicity; mutagen; mutation assay.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Biological Assay
  • Flow Cytometry
  • Male
  • Mutagenicity Tests*
  • Mutagens / pharmacology*
  • Mutagens / toxicity
  • Mutation / genetics*
  • Rats
  • Reticulocytes / drug effects*
  • Reticulocytes / pathology
  • Rodentia / genetics


  • Mutagens