Toxicity, mutagenicity and transport in Saccharomyces cerevisiae of three popular DNA intercalating fluorescent dyes.

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.

Paintomics: a web based tool for the joint visualization of transcriptomics and metabolomics data.

MOTIVATION: The development of the omics technologies such as transcriptomics, proteomics and metabolomics has made possible the realization of systems biology studies where biological systems are interrogated at different levels of biochemical activity (gene expression, protein activity and/or metabolite concentration). An effective approach to the analysis of these complex datasets is the joined visualization of the disparate biomolecular data on the framework of known biological pathways. RESULTS: We have developed the Paintomics web server as an easy-to-use bioinformatics resource that facilitates the integrated visual analysis of experiments where transcriptomics and metabolomics data have been measured on different conditions for the same samples. Basically, Paintomics takes complete transcriptomics and metabolomics datasets, together with lists of significant gene or metabolite changes, and paints this information on KEGG pathway maps. AVAILABILITY: Paintomics is freely available at http://www.paintomics.org.