Possible errors in the interpretation of ethidium bromide and PicoGreen DNA staining results from ethidium monoazide-treated DNA - PubMed (original) (raw)

Comment

Possible errors in the interpretation of ethidium bromide and PicoGreen DNA staining results from ethidium monoazide-treated DNA

Ingeborg Hein et al. Appl Environ Microbiol. 2006 Oct.

No abstract available

PubMed Disclaimer

Figures

FIG.1.

FIG.1.

Analysis of EMA-treated and EMA-untreated DNA on an ethidium bromide-stained agarose gel. EMA treatment was performed, as published recently, in a volume of 1 ml at a concentration of 100 μg EMA (Molecular Probes, Eugene, OR)/ml (3). The samples were incubated for 5 min at 4°C in the dark, followed by exposure to light in macrocuvettes (Greiner, Frickenhausen, Germany) for 2 min at a distance of 20 cm from the light source, using a Ventilux 1250 lamp and a 650-W halogen light bulb (Hedler, Runkel, Germany). Calf thymus DNA was obtained from Sigma-Aldrich (St. Louis, MO). Salmonella enterica serovar Typhimurium NCTC 12023 DNA was isolated from an overnight culture in tryptic soy broth with 0.6% yeast at 37°C using the NucleoSpin tissue kit (Machery-Nagel, Düren, Germany). Lane m, 100-bp ladders. Lanes marked with a contain samples of DNA exposed (exp.) to light without the addition of EMA.

FIG.1.

FIG.1.

Lysis matrix tubes with pelleted cell debris of viable and dead Salmonella and E. coli O157:H7 without (−) or with (+) previous EMA treatment. Culture aliquots were either processed directly without stress exposure, heat treated at 72°C for 15 min, or exposed to 70% isopropanol (isoprop.) for 10 min. Cells were pelleted by centrifugation. Cell pellets were resuspended and subjected to bead beating. Lysis matrix tubes are shown after centrifugation for 5 min at 14,000 × g, with the cell debris facing upward.

FIG. 2.

FIG. 2.

Lysis matrix tubes with pelleted cell debris of Salmonella exposed to heat stress at 72°C (1 to 15 min) with subsequent EMA treatment. Cells were pelleted by centrifugation. Cell pellets were resuspended and subjected to bead beating. Lysis matrix tubes are shown after centrifugation for 5 min at 14,000 × g, with the cell debris facing upward.

Comment on

Similar articles

Cited by

References

    1. Bolton, P. H., and D. R. Kearns. 1978. Spectroscopic properties of ethidium monoazide: a fluorescent photoaffinity label for nucleic acids. Nucleic Acids Res. 5:4891-4903. - PMC - PubMed
    1. Nocker, A., and A. K. Camper. 2006. Selective removal of DNA from dead cells of mixed bacterial communities by use of ethidium monoazide. Appl. Environ. Microbiol. 72:1997-2004. - PMC - PubMed
    1. Nogva, H. K., S. M. Drømtørp, H. Nissen, and K. Rudi. 2003. Ethidium monoazide for DNA-based differentiation of viable and dead bacteria by 5′-nuclease PCR. BioTechniques 34:804-813. - PubMed
    1. Rudi, K., H. K. Nogva, B. Moen, H. Nissen, S. Bredholt, T. Møretrø, K. Naterstad, and A. Holck. 2002. Development and application of new nucleic acid-based technologies for microbial community analyses in foods. Int. J. Food Microbiol. 78:171-180. - PubMed
    1. Yielding, L. W., and W. J. Firth III. 1980. Structure-function characterization for ethidium photoaffinity labels as mutagens in Salmonella. Mutat. Res. 71:161-168. - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources