Trace2O AquaSafe WSL25 Plus, Инструкция по эксплуатации

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SECTION 6: ASEPTIC PROCEDURES
Aseptic procedures are of paramount importance during microbiological analysis, and extra
care must be taken when outside the central laboratory, i.e. in the field.
Everything must be kept clean and sterile, particularly on the following surfaces:
Inner surface of the sampling cup
Inner surface of the graduated filter funnel
Filter membrane and absorbent pads
Upper surface of the sintered membrane support disc
Inside of the petri dishes
Support pad dispenser arm, and forceps
Before every use, rinse the filtration unit and sampling cup in clean water,
and dry by using clean tissue paper.
Pour approx. 1 mL of methanol into the sampling cup and swirl. (The methanol can be stored
in the plastic bottles provided).
Place the sample cup in a normal upright position, away from any flammable substances.
Using a suitable means (cigarette lighter), ignite the methanol – TAKE CARE AROUND THE
NAKED FLAME.
Allow the methanol to burn for a few seconds.
Whilst the
methanol is still burning, invert the filtration unit and carefully place inside the
sample cup.
Wait for at least 20 minutes to ensure that the sample cup and filtration unit are sterile.
Methanol burns anaerobically to form formaldehyde gas, which reaches all areas of the
filtration apparatus and ensures a thorough sterilisation.
Pour any residual methanol solution away.
The above sterilisation procedures should be carried out immediately before sampling, and
after the filtration of each sample.
Reusable aluminium petri dishes must be sterilized, either by immersing in boiling water, or
flaming with methanol prior to use. After sterilisation, ensure that the dishes are allowed to
dry thoroughly before use. Other methods of sterilisation can be employed, including
autoclaving, or placing the aluminium dishes in a conventional oven at 300°C for 30 minutes.
Once sterile, the petri dishes should be handled carefully to prevent subsequent
recontamination.