UNIT 20.3 The Syrian Hamster Embryo (SHE) Low pH Cell Transformation Assay

  1. Kamala Pant1,
  2. Marilyn J. Aardema2

Published Online: 1 FEB 2008

DOI: 10.1002/0471140856.tx2003s35

Current Protocols in Toxicology

Current Protocols in Toxicology

How to Cite

Pant, K. and Aardema, M. J. 2008. The Syrian Hamster Embryo (SHE) Low pH Cell Transformation Assay. Current Protocols in Toxicology. 35:20.3:20.3.1–20.3.16.

Author Information

  1. 1

    BioReliance, Rockville, Maryland

  2. 2

    The Procter and Gamble Company, Miami Valley Innovation Center, Cincinnati, Ohio

Publication History

  1. Published Online: 1 FEB 2008
  2. Published Print: FEB 2008


The Syrian hamster embryonic (SHE) cell transformation assay (CTA) at pH 6.7 can determine the ability of a test article to induce morphological transformation (MT) in cultured SHE cells. The assay uses SHE cells prepared at gestation day ∼13 and frozen. Target cells are seeded onto a layer of feeder cells (X-ray irradiated SHE cells) and treated with test article for 24 hr or 7 days. After a growth period of 7 days, the cells are fixed, stained, and evaluated for MT. Normal colonies typically contain a monolayer of cells with an organized, often flowing, pattern of growth and minimal cell criss-crossing at a confluent density. Transformed colonies contain randomly oriented, stacked cells, with cell criss-crossing throughout the colony. The transformed cells are frequently more basophilic than their normal counterparts, with increased nuclear/cytoplasmic ratios. This assay provides a valuable tool for evaluating the carcinogenic potential of a test article. Curr. Protoc. Toxicol. 35:20.3.1-20.3.16. © 2008 by John Wiley & Sons, Inc.


  • SHE;
  • morphological transformation;
  • clonal transformation;
  • foci formation;
  • colony transformation;
  • in vitro carcinogenicity prediction