Comparison of blue nucleic acid dyes for flow cytometric enumeration of bacteria in aquatic systems.
Seven blue nucleic acid dyes from Molecular Probes Inc. (SYTO-9, SYTO-11, SYTO-13, SYTO-16, SYTO-BC, SYBR-I and SYBR-II) were compared with the DAPI (4',6-diamidino-2-phenylindole) method for flow cytometric enumeration of live and fixed bacteria in aquatic systems. It was shown that SYBR-II and SYTO-9 are the most appropriate dyes for bacterial enumeration in nonsaline waters and can be applied to both live and dead bacteria. The fluorescence signal/noise ratio was improved when SYTO-9 was used to stain living bacteria in nonsaline waters. Inversely, SYBR-II is more appropriate than SYTO dyes for bacterial enumeration of unfixed and fixed seawater samples.
Lebaron
P
P
Observatoire Océanologique, Centre National de la recherche Scientifique, Institut National des Sciences de l'Univers et Université Pierre et Marie Curie, Banyuls-sur-Mer, France. lebaron@arago.obs-banyuls.fr
Parthuisot
N
N
Catala
P
P
D015169:Colony Count, Microbial; D004396:Coloring Agents; D004269:DNA, Bacterial / Q000032:analysis*; D005434:Flow Cytometry; D012329:RNA, Bacterial / Q000032:analysis*; D013194:Staining and Labeling; D014871:Water Microbiology
D004396:Coloring Agents; D004269:DNA, Bacterial; D012329:RNA, Bacterial