title: Toxicity, mutagenicity and transport in Saccharomyces cerevisiae of three popular DNA intercalating fluorescent dyes.
abstract: We have compared the toxicity, mutagenicity and transport in Saccharomyces cerevisiae of three DNA-intercalating fluorescent dyes widely used to stain DNA in gels. Safety data about ethidium bromide (EtBr) are contradictory, and two compounds of undisclosed structure (Redsafe and Gelred) have been proposed as safe alternatives. Our results indicate that all three compounds inhibit yeast growth, with Gelred being the most inhibitory and also the only one causing cell death. EtBr and Gelred, but not Redsafe, induce massive formation of petite (non-respiratory) mutants, but only EtBr induces massive loss of mitochondrial DNA. All three compounds increase reversion of a chromosomal point mutation (lys2-801(amber) ), with Gelred being the most mutagenic and Redsafe the least. These dyes are all cationic and are probably taken by cells through non-selective cation channels. We could measure the glucose-energized transport of EtBr and Gelred inside the cells, while uptake of Redsafe was below our detection limit. We conclude that although all three compounds are toxic and mutagenic in the yeast system, Redsafe is the safest for yeast, probably because of very limited uptake by these cells.
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-CSIC, Valencia, Spain.
authors.forename: Enric
authors.initials: E
authors.lastname: Sayas
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-CSIC, Valencia, Spain.
authors.forename: Federico
authors.initials: F
authors.lastname: García-López
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-CSIC, Valencia, Spain.
authors.forename: Ramón
authors.initials: R
authors.lastname: Serrano
mesh_terms: D004996:Ethidium / Q000378:metabolism / Q000633:toxicity; D005456:Fluorescent Dyes / Q000378:metabolism / Q000633:toxicity*; D007364:Intercalating Agents / Q000378:metabolism / Q000633:toxicity*; D009153:Mutagens / Q000378:metabolism / Q000633:toxicity*; D009154:Mutation / Q000187:drug effects; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
chemical_list: D005456:Fluorescent Dyes; D007364:Intercalating Agents; D009153:Mutagens; D004996:Ethidium
keywords: Gelred; Redsafe; dye uptake; ethidium bromide; growth inhibition; mutation reversion; non-selective cation channels; petite induction