Water samples are taken in accordance with the standard SFS-EN ISO 19458:2007.
Follow these steps
- Arrange the sampling in advance by email or telephone.
- Prepare the necessary supplies for sampling and collect the samples.
- Deliver the samples to the laboratory in Kuopio so that they arrive the next morning. Remember to complete the analysis order form and a DEUF form carefully, either electronically at your workstation or by hand. You may submit the form by email or as a paper copy with the samples.
- THL will confirm receipt of the samples by email or telephone.
Analyysitilauslomake vesimikrobiologisille analyyseille (in Finnish)
Näytetietolomake DEUF-näytteille (in Finnish)
Large‑volume sampling (DEUF)
Using Dead‑end ultrafiltration (DEUF) technique, large volumes of water can be filtered through a filter cartridge, allowing microorganisms to be retained on the ultrafilter. Depending on the sampling site, the filtered water can be directed either to the sewer or into the environment. When analysing drinking water, the most common filtration volume is 100 litres.
After filtration, send the filter cartridge to THL’s Microbiology Unit, laboratory of water microbiology, for examination. Include a carefully completed DEUF sample information form and an analysis order form either in paper form with the sample or separately by email. Forms may be completed electronically or by hand.
Näytetietolomake DEUF-näytteille (in Finnish)
Sample volumes
The analysis of Cryptosporidium and Giardia protozoa requires large-volume DEUF sampling.
The required sample volume depends on the sample matrix and should be agreed upon with the laboratory when arranging the sampling. For drinking water, the sample volume is typically at least 100 liters.
Shipping of samples
- Send samples in a cool box with several chilled ice packs.
- The temperature during transport should be approximately +5 °C, and the sample must not freeze.
- Measure the water temperature at the time of sampling (not directly from the sample container to avoid contamination).
- Samples should arrive at the laboratory as soon as possible after sampling.
Microbiological results can be considered reliable if analysis is started within approximately 24 hours of sampling (depending on the microorganism, acceptable times range from 12 hours to 4 days). In suspected outbreak situations, older samples may also be analysed, but only positive findings are considered reliable.
Sample shipping address
Finnish Institute for Health and Welfare (THL)
Microbiology Unit
Laboratory of water microbiology (name of contact person)
P.O. Box 95 (Neulaniementie 4)
FI-70701 Kuopio, Finland