ATLAS BIOTECNOLOGIES AB10000 Manual de instrucciones - Página 5

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• If the desired volume is lower than set volume shown
by the counter, the operator should turn the pipetting
pushbutton (Fig. 1A2) or the black adjustment knob
(Fig. 1B) to the direction diminishing counter readings
to the required volume. Before achieving the required
volume slowly rotate the knob and observe carefully
diminishing reading to avoid accidentally passing the
setting value.
• If the desired volume is higher than set volume shown
by the counter, the operator should turn the pipetting
pushbutton (Fig. 1A2) or the black adjustment knob
(Fig. 1B) increasing the value until the lower figure
wheel comes 1/3 of a turn beyond the required setting
and then slowly backward until the setting reaches the
desired volume. Make sure not to pass the setting
value.
If the knob is accidentally turned too far, the process
must be repeated. The desired volume must always be
set from the higher value in the order of decreasing value.

3 - ASPIRATING AND DISPENSING LIQUIDS

Place a tip on the shaft of the pipette. See section 6 for
the appropriate tip. Press the tip on firmly using a slight
twisting motion to en sure a positive, airtight seal.
Important: Never aspirate liquids into the pipette
without a tip attached.
Aspiration
Press the pushbutton to the first positive stop, (Fig. 2A).
Holding the pipette vertically, immerse the tip into the
sample liquid. The depth to which the tip is immersed in
the sample liquid depends on the model.
Model
AB2
AB10
AB20, AB50, AB100
AB200, AB250, AB1000
AB5000
AB10000
Release the pushbutton slowly and smoothly to aspirate
the sample, (Fig. 2B). Wait one second and then with-
draw the tip from the liquid. When the pipette tip is
immersed not as deeply as the recommended depth or
5
Immersion depth (mm)
≤ 1
≤ 1
2 ÷ 3
2 ÷ 3
3 ÷ 6
5 ÷ 7
when the pipetting pushbutton is rapidly released air
may enter the disposable tip.
Avoid touching the orifice of the tip.
Dispensing
• Place the end of the tip against the inside wall of the
vessel at an angle of 10 to 40 degrees.
• Press the pushbutton smoothly to the first stop, (Fig. 2C).
Wait one second.
• Press the pushbutton to the second stop to expel any
remaining liquid, (Fig. 2D).
• Keeping the pushbutton depressed to the very end,
remove the pipette by drawing the tip against the inside
surface of the receiving vessel.
• Release the pushbutton to its starting position, (Fig. 2E).
• Eject the tip by pressing the tip ejector button, (Fig. 2F).
Remember to change the tip whenever a different kind
of liquid is to be sampled.

4 - PRE-RINSING

When pipetting liquids of higher viscosity or lo wer surface
tension than water (e.g. sera or or ga nic solvents), a film
of liquid is formed on the inside wall of the pipette tip.
This film can create an error. Since the film remains rela-
tively constant in successive pipetting operations with
the same tip, this error can be avoided by forming the
film before transferring the first sample. This is done by
aspirating a sample and dispensing it back into the same
vessel. Since the film is already formed, all of the follow-
ing samples will have better accuracy and repeatability.
This pre-rinsing operation should be repeated when the
vo lume to be aspirated is changed or when a new tip is
used.

5 - DENSE AND VISCOUS LIQUIDS

The pipette specifications of accuracy and precision are
based on pipetting distilled water. The handling of liquids
with physical qualities of density, viscosity and surface
tension differing extremely from water may need a gravi-
metrically checked compensation of the volume setting.
Normally the degree of error resulting from heavy or vis-
cous liquids is negligible if the pipetting is done slowly
and carefully. It is most important to give the liquids
ENGLISH
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