Sterile swabs can be used to test the level of microbial contamination on various surfaces such as air conditioning units, kitchen equipment, hospital wards, spas or any other place. Swab samples can be analysed for total viable counts (usually referred to as colony forming units) or specific indicator organisms for food spoilage or sewage contamination. Swab samples are easy to collect.
How To Collect Swab Samples
- Wear gloves
- Select a sampling area of about 10 cm X 10 cm (or 20 cm x 20 cm)
- Break the seal round the tube containing the swab
- Remove the swab from the tube and rub and roll it firmly several times across the sampling area.
- Return the swab into the tube and label the sample
- Send the sample to the laboratory for analysis.
If one is sampling a dry surface, it is recommended that a wet or moistened swab is used. The swab test method has proved a popular testing method with flood damage insurance claims, where there may be sewage contamination. If swab samples are collected for culture analysis, they should be sent to the laboratory within 24 hours after collection. If the analysis of the swab samples involves enumeration of the microbial contaminants, the size of the area sampled should be provided to the lab.