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SECTION 8 – CLEANING AND DECONTAMINATION
8.1
CLEANING
Wiping the sample from both the upper and lower read heads upon completion of each sample
measurement with a lint free cloth is usually sufficient to prevent sample carryover and avoid residue
buildup. Although generally not necessary, water aliquots can be used to clean the measurement
surfaces after the measurement of particularly highly concentrated samples to ensure no residual
sample is retained on either read head. After measuring a large number of samples, it is recommended
that the areas around the upper and lower pedestals are cleaned thoroughly. This will prevent spread
of contamination from previous samples onto the measurement pedestals which could affect subsequent
low-level measurements. A final cleaning of all surfaces with deionised water is also recommended after
the last measurement.
8.2
DECONTAMINATION
If decontamination is necessary, a sanitising solution, such as a 0.5% solution of sodium hypochlorite
(1:10 dilution of common commercial bleach solutions – freshly prepared), can be used to ensure that
no biologically active material is present on the measurement read heads. The read head fittings are
made from stainless steel and are resistant to most common laboratory solvents. See Section 13 -
Chemical Compatibility for full details.
8.3
READ HEAD RECONDITIONING
Reagents containing surfactants can “un-condition” the measurement read head surfaces so that the
liquid does not form a stable sample droplet. If this occurs, “buff” the read head surfaces by rubbing
each measurement surface aggressively with a dry laboratory wipe 30-40 times. This will “re-condition”
the surface allowing the sample droplet to form.
