水中微生物의 計數方法은 크게 둘로 나누인다. 첫째 方法은 replicon槪念에 基礎를 둔 것으로 살아있는菌과 죽은 菌을 구별할 수 있으나 使用되는 培地가 生理的으로 다른 多樣한 細菌들로 구성된 水中細菌의 生育에 적합하지 않아서 全 細菌數를 計數할 수 없다.
둘째 方法은 직접 검경하여 計數하는 方法으로 살아있는 菌과 죽은菌, 細菌과 particle의 區別이 곤란하다. 그러나 최근 細菌染色術의 發達로 水中細菌을 肉眼으로 쉽게 區別하여 計數할 수 있는 方法이 可能하게 되었다. 이 方法은 螢光顯徵鏡을 使用하여 acridine orange로 染色된 水中의 全細菌數를 測定하는 方法이다.
따라서 本 硏究는 上水道源의 細菌汚染度를 測定하는데 새로운 方法으로서 epifluorcscence microscopy를 提示하는데 있으며 이의 使用性可能與否를 診斷하기 위해 chlorine과 chloramine을 試料水에 處理하여 경시적으로 細菌數를 調査하여 平板法과 比較하였다.
試料水(sample water)의 全細菌數는 螢光檢鏡法에 依해 正確히 測定되었으며 分離能力(resolution)에 있어서 卓越하였고 또한 經濟的이고도 간편하였다. 그리고 消毒殺菌劑로는 chloramine이 監素보다 水中細菌에 미치는 影響은 훨씬 컸다.
Methods for the measurement of aquatic bacteria can be divided into two groups. The first group of these methods is based on the `replicon` concept that live bacterial cells, when diluted and transferred to a suitable medium, produce colonies. These methods distinguish living from dead bacteria, but they massively underestimate bacterial numbers. The second group of enumeration methods uses visual counting technique using specific apparatus such as a microscope. These methods are generally direct and simple, but it is very hard to distinguish between live and dead bacteria and between small particle and bacteria. Recently developed technique in staining methods has provided a reliable method of visual determination of aquatic bacteria. This uses epifluorescence microscopy to measure the total bacterial population. In order to present the fluorescence microscopy as a new methodology for the determination of bacterial numbers in water supplies, data were obtained from chlorine and monochloramine doses added to samples. Total counts by fluorescence microscopy were compared with standard plate count method. The total number of bacteria in water supplies can be determined with fluorescence microscopy. This technique allows better resolution of small bacteria and differentiation of particle from bacteria. Chloramine was found to persist longer in natural waters and prevent bacterial regrowth.