title: Fluorescence characteristics of sodium fluorescein-rose bengal ophthalmic solution mixtures.
abstract: OBJECTIVE
  To assess fluorescence emission properties of sodium fluorescein-rose bengal mixtures in buffered aqueous solution.
  
  
  METHODS
  Solutions of sodium fluorescein (NaFl) or rose bengal (RB) or mixtures of these two chemicals were prepared over a range of dilutions in 1% NaCl with 10mM phosphate buffer to give a pH of 7.5 at room temperature. Absorbance and fluorescence spectra were recorded in 10mm path length cuvettes.
  
  
  RESULTS
  The fluorescence emission from NaFl extends between 480 and nearly 600nm, a spectral range that is also covered by the absorbance of RB (between 500 and 580nm). With very dilute solutions of NaFl (less than 0.002%), an apparent total quenching of its fluorescence can occur in the presence of 0.01% RB, with a proportionate decrease at lower concentrations of RB.
  
  
  CONCLUSIONS
  The presence of RB in an aqueous solution of NaFl at physiological pH appears to act in a similar way to a barrier filter, resulting in the quenching of the measurable fluorescence from NaFl. It remains to be established how substantial or significant such an effect might be if a mixture of NaFl and RB as used as part of the examination of the external eye.
authors.affiliation: Glasgow-Caledonian University, Department of Vision Sciences, Cowcaddens Road, Glasgow G4 OBA, United Kingdom. Electronic address: m.doughty@gcal.ac.uk.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Doughty
mesh_terms: D004338:Drug Combinations; D019793:Fluorescein / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D009883:Ophthalmic Solutions / Q000737:chemistry*; D015203:Reproducibility of Results; D012395:Rose Bengal / Q000737:chemistry*; D013053:Spectrophotometry
chemical_list: D004338:Drug Combinations; D005456:Fluorescent Dyes; D009883:Ophthalmic Solutions; D012395:Rose Bengal; D019793:Fluorescein
keywords: Cornea; Fluorescein; Rose bengal; Tear film