| 摘要 |
Bacteria, particularly coliform bacteria, present in a liquid, are rapidly detected. A sample of the liquid to be tested is admixed with an enzyme-inducing agent which induces the production of an enzyme in the bacteria, the enzyme being capable of reacting with a fluorescent conjugate ingested by the bacteria to release its fluorescent portion. Conditions are controlled such that a sufficient number of molecules of enzyme are produced per bacterium present in the liquid sample to effect release of the fluorescent portion. A fluorescent conjugate, capable of being ingested by the bacteria, is admixed with the liquid sample for reaction with the enzyme to release the fluorescent portion of the fluorescent conjugate. The liquid sample is then formed into microdroplets in a liquid carrier such that the fluorescent material is retained in the microdroplets. A liquid carrying the microdroplets is formed into a stream in which the microdroplets become aligned and the stream is moved relative to a detector for detecting fluorescence. The detected fluorescence provides a measure of the quantity of bacteria in the liquid sample. By proceeding in this manner, it is possible to quantify the bacteria, at a level down to two per ml, in less than two hours. Apparatus suitable for the method is also disclosed. |
