Photobleaching of red fluorescence in oral biofilms
Photobleaching of red fluorescence in oral biofilms
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DOI：
10.1111/j.1600-0765.2010.01334.x
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发表时间：
2011-04-01
影响因子：
3.5
通讯作者：
Higham, S. M.
中科院分区：
文献类型：
--
作者：
Hope, C. K.;de Jong, E. de Josselin;Higham, S. M.
背景和目的：由于内源性卟啉的存在，许多口腔细菌可以被诱导发出荧光，这种现象可用于在实验室或临床环境中可视化和量化牙菌斑。然而，荧光不可避免的后果是光漂白，其对牙菌斑纵向定量分析的影响尚未确定。材料和方法：滤膜生物膜由唾液接种物或单一物种（黑普雷沃菌和中间普雷沃菌）生长。然后在定制的照明装置中检查成熟的生物膜，该装置包括能够向样品提供 220 W/m2 的 405 nm 发光二极管、适当的滤光器和数码相机；类似于定量光诱导荧光数字的设置。捕获并处理纵向图像集，以评估红色荧光随时间的退化。结果：在所有情况下都观察到光漂白。在开始照射后立即观察到最高的光漂白率，特别是在第一分钟内。在暴露的第一分钟内，P. nigrescens 生物膜、微观世界生物膜和 P. intermedia 生物膜的光漂白相对速率分别为 19.17、13.72 和 3.43 任意单位/分钟。结论：在原位定量测量卟啉荧光时，光漂白可能会出现问题。在进行定量光诱导荧光数字分析时，默认方法应是减少光照水平和曝光时间，同时提高相机灵敏度。
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 utilized to visualize 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 have 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 405 nm light-emitting diodes capable of delivering 220 W/m2 at the sample, an appropriate filter and a digital camera; a set-up analogous to quantitative light-induced fluorescence digital. 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 the first minute. Relative rates of photobleaching during the first minute of exposure were 19.17, 13.72 and 3.43 arbitrary units/min for P. nigrescens biofilms, microcosm biofilm and P. intermedia biofilms, 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 quantitative light-induced fluorescence digital.