title: Quantification of total RNA by ethidium bromide fluorescence may not accurately reflect the RNA mass.
abstract: The fluorescent signal from purified large and small ribosomal RNA subunits stained with ethidium bromide was quantified using agarose gels and image analysis. A significantly smaller fluorescent signal was observed for 23 S rRNA compared to 16 S rRNA when normalized to mass. Therefore, small changes in amounts of 23 S or 16 S rRNA within a sample can have a profound impact on observed bulk fluorescence. A comparison of 23 S/16 S rRNA fluorescence ratios for 4 marine bacteria grown in batch culture indicates that the lower fluorescence of 23 S rRNA is widespread. The 23 S/16 S rRNA fluorescence ratios also suggest that intracellular concentrations of ribosomal subunits do not always adhere to a stoichiometry of 2.0.
authors.affiliation: Institute of Marine and Coastal Sciences, State University of New Jersey, New Brunswick 08903-0231, USA. kerkhof@ahab.rutgers.edu
authors.forename: L
authors.initials: L
authors.lastname: Kerkhof
mesh_terms: D004996:Ethidium; D005453:Fluorescence; D011549:Pseudomonas / Q000235:genetics*; D012329:RNA, Bacterial / Q000032:analysis*; D012680:Sensitivity and Specificity
chemical_list: D012329:RNA, Bacterial; D004996:Ethidium