Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf 8600, Switzerland.
Cytometry A. 2012 Jun;81(6):508-16. doi: 10.1002/cyto.a.22048. Epub 2012 Apr 4.
Accurate and sensitive online detection tools would benefit both fundamental research and practical applications in aquatic microbiology. Here, we describe the development and testing of an online flow cytometer (FCM), with a specific use foreseen in the field of drinking water microbiology. The system incorporated fully automated sampling and fluorescent labeling of bacterial nucleic acids with analysis at 5-min intervals for periods in excess of 24 h. The laboratory scale testing showed sensitive detection (< 5% error) of bacteria over a broad concentration range (1 × 10(3) -1 × 10(6) cells mL(-1) ) and particularly the ability to track both gradual changes and dramatic events in water samples. The system was tested with bacterial pure cultures as well as indigenous microbial communities from natural water samples. Moreover, we demonstrated the possibility of using either a single fluorescent dye (e.g., SYBR Green I) or a combination of two dyes (SYBR Green I and Propidium Iodide), thus broadening the application possibilities of the system. The online FCM approach described herein has considerable potential for routine and continuous monitoring of drinking water, optimization of specific drinking water processes such as biofiltration or disinfection, as well as aquatic microbiology research in general.
准确、灵敏的在线检测工具将有益于水生微生物学的基础研究和实际应用。在这里，我们描述了一种在线流式细胞仪（FCM）的开发和测试，该仪器在饮用水微生物学领域有特定的用途。该系统采用全自动采样和细菌核酸荧光标记，每隔 5 分钟进行分析，持续时间超过 24 小时。实验室规模的测试表明，该系统能够在较宽的浓度范围内（1×10(3)-1×10(6)细胞 mL(-1))对细菌进行灵敏检测（<5%误差），特别是能够跟踪水样中逐渐变化和剧烈事件。该系统经过了细菌纯培养物以及天然水样中土著微生物群落的测试。此外，我们还证明了使用单一荧光染料（如 SYBR Green I）或两种染料（SYBR Green I 和碘化丙啶）的组合的可能性，从而拓宽了该系统的应用可能性。本文所述的在线 FCM 方法在饮用水的常规和连续监测、特定饮用水处理过程（如生物过滤或消毒）的优化以及一般的水生微生物学研究方面具有很大的潜力。
