Mind your assays: Misleading cytotoxicity with the WST-1 assay in the presence of manganese

PLoS One. 2020 Apr 16;15(4):e0231634. doi: 10.1371/journal.pone.0231634. eCollection 2020.

Abstract

The WST-1 assay is the most common test to assess the in vitro cytotoxicity of chemicals. Tetrazolium-based assays can, however, be affected by the interference of tested chemicals, including carbon nanotubes or Mg particles. Here, we report a new interference of Mn materials with the WST-1 assay. Endothelial cells exposed to Mn particles (Mn alone or Fe-Mn alloy from 50 to 1600 μg/ml) were severely damaged according to the WST-1 assay, but not the ATP content assay. Subsequent experiments revealed that Mn particles interfere with the reduction of the tetrazolium salt to formazan. Therefore, the WST-1 assay is not suitable to evaluate the in vitro cytotoxicity of Mn-containing materials, and luminescence-based assays such as CellTiter-Glo® appear more appropriate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Survival / drug effects
  • Cytotoxins / toxicity*
  • Endothelial Cells / cytology
  • Endothelial Cells / drug effects*
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Luminescent Measurements / methods
  • Manganese / toxicity*
  • Oxidation-Reduction
  • Tetrazolium Salts / chemistry
  • Toxicity Tests / methods

Substances

  • Cytotoxins
  • Tetrazolium Salts
  • Manganese

Grants and funding

ES is financed by the “Communauté française de Belgique. Sections de Recherche Concertées” [contract 15/20-066]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.