Skip navigation
Scholarly Communication

Photobleaching of red fluorescence in oral biofilms

Hope, C.K.; de Josselin de Jong, E.; Field, M.R.T.; Valappil, S.P. and Higham, S.M. (2011) Photobleaching of red fluorescence in oral biofilms. Journal of Periodontal Research, 46 . pp. 228-234. ISSN 1600-0765 (Online); 0022-3484 (Print)

PDF (pre-print) - Submitted Version
PDF (Publisher's legend for pre-print)

Cited 0 times in WoS


Background and Objective: Many species of oral bacteria can be induced to fluoresce due to the presence of endogenous porphyrins, a phenomenon that can be utilised to visualise and quantify dental plaque in the laboratory or clinical setting. However; an inevitable consequence of fluorescence is photobleaching, and the effects of this on longitudinal, quantitative analysis of dental plaque has yet to be ascertained. Material and Methods: Filter membrane biofilms were grown from salivary inocula or single species (Prevotella nigrescens and Prevotella intermedia). The mature biofilms were then examined in a custom-made lighting rig comprising of 405 nm light emitting diodes capable of delivering W m-2 at the sample, an appropriate filter and a digital camera; a set-up analogous to quantitative light-induced fluorescence digital (QLFD). Longitudinal sets of images were captured and processed to assess the degradation in red fluorescence over time. Results: Photobleaching was observed in all instances. The highest rates of photobleaching were observed immediately after initiation of illumination, specifically during 33 the first minute. Relative rates of photobleaching during the first minute of exposure were; 19.17, 13.72, and 3.43 (arbitrary units per minute) for P. nigrescens biofilms, microcosm biofilm and P. intermedia respectively. Conclusion: Photobleaching could be problematic when making quantitative measurements of porphyrin fluorescence in situ. Reducing both light levels and exposure time, in combination with increased camera sensitivity, should be the default approach when undertaking analyses by QLFD.

Item Type:Article
Additional Information:First published online: 28 December 2010. Additional citation information : Issue 2, April 2011. Cited as : Hope, C. K., de Josselin de Jong, E., Field, M. R. T., Valappil, S. P. and Higham, S. M. (2011), Photobleaching of red fluorescence in oral biofilms. Journal of Periodontal Research, 46: 228–234. doi: 10.1111/j.1600-0765.2010.01334.x . Online version of published article includes additional supporting information.
Uncontrolled Keywords:Oral biofilm; plaque; fluorescence; quantitative light-induced fluorescence digital; QLFD; porphyrin; photobleaching
Subjects:R Medicine > RK Dentistry
Departments, Research Centres and Related Units:Academic Faculties, Institutes and Research Centres > Faculty of Medicine > School of Dental Sciences
ID Code:1442
Deposited On:24 Feb 2011 17:01
Last Modified:16 Apr 2012 16:26

Repository Staff Only: item control page


Full text only
Peer reviewed only

Cross Archive Search
Top 50 authors
Top 50 items
[more statistics]

These pages are maintained by Library Staff @ University of Liverpool Library


All pages © The University of Liverpool, 2004 | Disclaimer | Accessibility | Staff | Students