Loehr R C, Schwegler D T
Appl Microbiol. 1965 Nov;13(6):1005-9. doi: 10.1128/am.13.6.1005-1009.1965.
A filtration method has been developed which can be used to detect and enumerate phage in low concentrations directly from solution without the need for prior concentration. In this method, a known volume of the phage solution is mixed with a suitable host solution. Samples are filtered through membrane filters; the filter is removed and incubated, and after 24 hr the resultant plaques are counted and the titer is calculated. Escherichia coli B and the coliphage T2 were used in these studies. Host cultures less than 12 hr old produced the best results. Approximately 10(10) host organisms must be present in the sample taken for filtration. To avoid phage reproduction, all steps prior to filtration must be done in less than 45 min. The method was compared with the soft-agar technique and was shown to be less precise but able to measure phage in lower concentrations.
已开发出一种过滤方法，可直接从溶液中检测和计数低浓度的噬菌体，无需事先浓缩。在该方法中，将已知体积的噬菌体溶液与合适的宿主溶液混合。样品通过膜过滤器过滤；取出过滤器并进行培养，24小时后对产生的噬菌斑进行计数并计算效价。这些研究中使用了大肠杆菌B和大肠杆菌噬菌体T2。培养时间少于12小时的宿主培养物产生的结果最佳。用于过滤的样品中必须存在约10(10)个宿主生物体。为避免噬菌体繁殖，过滤前的所有步骤必须在45分钟内完成。该方法与软琼脂技术进行了比较，结果表明其精度较低，但能够测量更低浓度的噬菌体。
