Easicult is a dipslide method designed for monitoring microbes in water and industrial fluids. When present in great numbers, microbes may pose a risk to health and lead to corrosion and circulation problems.
Easicult dipslides do not specifically indicate the presence of legionella bacteria, but are for use to indicate trends in microbiological quality. Dipslides should only be used after a system has been cleaned and disinfected, and an effective water treatment regime set up.
Dipslides will show whether the treatment continues to be effective and to indicate if remedial action, such as cleaning or disinfection, should be taken.
Sampling should be carried out on a regular basis, from the same location each time.
NOTE: It is also vital for meaningful results that the incubation period, temperature and location be identical each time the test is carried out on a particular water system.
APPLICATION & USAGE:
1. Unscrew the tube and withdraw the slide without touching the agar coated surfaces.
2. Take a sample of the water to be tested in a container and dip the slide into it. Both agar surfaces should be completely wet. (see right)
3. Allow excess fluid to drain off the slide. Blot the lower edge of the slide on clean absorbent paper. (see right)
4. Screw the slide tightly back into the tube.
5. Fill in the label and affix it to the tube.
6. Place the tube upright, in a warm place, or incubator at a temperature of 27°C to 30°C. Temperatures above 30°C may dehydrate the agar and give inconsistent results.
7. After 24 hour incubation (in incubator), remove the slide from the tube and compare the density of the colonies growing on the agar medium with the model density chart, without counting the colonies. If the incubation takes place at room temperature, the results should be read after 2-3 days. (see right)
Easicult TTC - Interpretation of results
Nearly all aerobic bacteria grow on Easicult TTC dip slides. Fungi and yeasts may also grow slowly. Most bacteria give rise to red colonies. The bacterial count / ml of the sample is determined by comparing the density of the colonies appearing on the slide with the densities shown on the model chart on the accompanying folded leaflet.
If there are also colourless colonies present, these should also be taken into account when estimating the density of growth. In cases where large colonies occur, it should be remembered that it is the quantity of the colonies which is important, and not their size.
If the bacterial content is very high (over 107/ml), there is a confluent growth of bacteria, appearing as a uniformly red surface. Very rarely, there may be a totally colourless growth, which may be misinterpreted as a negative result, and it is advisable in doubtful cases to compare the incubated slide with an unused one. It is not possible to give any universally valid limits, however the following general guidelines may be used:
Bacterial count:
104 slight infection - probably acceptable.
105 or more moderate infection - take immediate action to clean / sterilise system
Disposal of used slides:
As the incubated slides are bacterial cultures, they should be handled carefully. Disposal of used slides can best be achieved by burning them, by immersing both slide and container in a disinfectant overnight, or by autoclaving them after loosening the caps.
Storage:
Unopened Easicult tubes should be stored at room temperature ( about 20°C / 68°F ) protected from light and draught. The expiry date is marked on the box. Easicult slides must not be frozen. Slides showing a bacterial growth, although unopened, are not usable.
