Biotech specialist Partec has released analytical instruments which use a novel method to determine bacterial counts in drinking water.
Partec says that the method is rapid and reliable and has been recommended by the Swiss Federal Office of Public Health.
A novel technique for determining micro-organism counts is helping to ensure the safety of drinking water. Using specially developed analytical instruments from German biotech company Partec, it is now possible to determine the microbiological status of drinking water rapidly. The procedure can be carried out at water companies, in distribution networks and at end consumers. Mobile testing is also possible.
The technique, called ‘Determination of total cell count and the quantitative relationship between cells with low and high nucleic acid content in fresh water by means of flow cytometry’, is quick, reliable and cost-effective. It enables bacterial contamination in drinking water to be characterised in less than 15 minutes and has been added to the Swiss Federal Office of Public Health’s Food Codex as a recommended technique. In addition to time-consuming conventional routine checks, water companies and cantonal and state analytical laboratories now have access to an innovative technique able to be used as an early warning parameter or for on-going monitoring. A pilot system for online microbial monitoring has already been implemented at a waterworks operated by the City of Zürich.
The driving force behind the new development is the Environmental Microbiology Department at the Swiss Federal Institute of Aquatic Science and Technology (Eawag), located in the town of Dübendorf. After several years of collaboration, researchers from Eawag and Partec have succeeded in using flow cytometry, a technique previously used predominantly for cellular analysis for medical applications, to determine drinking water quality. The technique involves marking individual bacterial cells with a fluorescent marker and using fluorescence detection to count and characterise them in a laser beam. A stand-out feature of the technique is its ability to count large numbers of bacteria in just a few seconds. The new method dispenses entirely with the need for time-consuming bacterial cultivation in Petri dishes. By analysing samples in an automated unit (for example, the CyFlow flow cytometer from Partec), it is possible to process more than 50 separate water samples per hour.
Partec has also realised the technical adaptation of its analytical instruments to meet the needs of mobile and online drinking water quality checks. As part of an Eawag project sponsored by the Berne-based Commission for Technology and Innovation CTI, the technique has been validated by an alliance of 14 Swiss and German institutions, including water companies, public and private analytical laboratories and research institutes. The technique has recently been awarded the status of a standard operating procedure in Switzerland’s Food Codex.
