VWR Signature ME50 Manual page 5

VWR-EHP-180-07-2008 OK
2 - SETTING THE VOLUME
Volume is set using the pipetting pushbutton (Fig. 1A2)
or adjustment knob (Fig. 1B), while the value is shown on
the digital counter. The volume shown by the counter is
represented by three digits which should be read from top
to bottom. Typical readings are shown in the following
table:
Counter
Model
readings
0
VWR ME10
3
VWR MT10
5
0
VWR ME50
6
VWR MT50
5
0
VWR ME200
8
VWR MT200
5
2
VWR ME300
5
VWR MT300
0
The volume adjustment can be performed when the locking
ring is set in the lower position (Fig. 5A). When the
desired volume is selected, the locking ring should be
set in the upper position (Fig. 5B).
To attain the maximum accuracy, set volume must be
approached from a higher value. If the desired value is
lower than the previous value, simply use the knob in the
pushbutton (Fig. 1A2) or the adjustment knob
(Fig. 1B) to adjust the value down to 1/3 turn above
the required setting. If the desired value is higher than
the previous value, use the knob in the pushbutton or the
adjustment knob to adjust the value to 1/3 turn above the
required value. The setting should then be performed in
the following manner:
With the volume set to 1/3 above the required setting,
slowly turn the pipetting pushbutton knob or the adjust-
ment knob to the required volume.
If the knob is accidentally turned too far, ie is set lower
than the required value, the process must be repeated.
The approach to the set volume must always be made in
the order of decreasing value.
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Set Basic
volume degree
3.5 μl 0.02 μl
6.5 μl 0.10 μl
85.0 μl 0.20 μl
250.0 μl 1.0 μl
Following volume adjustment, set the locking ring into
the upper position, thus locking the knob and preventing
accidental volume change.
3 - METHOD OF PIPETTING
Fit the tips onto the cones of the multichannel manifold.
While holding the pipettor in a vertical position, tips
should be immersed in the liquid to a depth of 2-4 mm,
and flushed once by drawing a dose of liquid and dis-
pensing it out with slow and steady movement.
Next, still holding the pipettor vertically, press the pipetting
button until the first resistance point is felt (Fig. 3A), and
immerse the tips in the liquid to the depth of 2-4 mm.
Releasing the pipetting button with a slow and uniform
movement during 2-3 seconds, the liquid should be
drawn into the tips (Fig. 3B) which should then be lifted
above the liquid's surface. The pipettor should next be
positioned at an angle of 10-45° in relation to inner walls
of destination vessels and the tips should be emptied
by pressing the pipetting button slowly until the first
resistance point is felt (Fig. 3C). After waiting a second,
the pipetting button should be pressed to the second
resistance point in order to expel remaining liquid
(Fig. 3D). Then the tips should be lifted out from the
vessels while maintaining contact between the ends
of the tips and the inner walls of the vessel until the
pipetting button has been released. Finally, press the
ejector button to separate the tips from multichannel
manifold's cones and dispose of properly (Fig. 3F).
4 - RECOMMENDATIONS
The recommendations below will ensure maximum accu-
racy and precision from your VWR Signature
- When pipetting, the VWR Signature
should have the volume setting locked with the lock-
ing ring in the upper position.
- Do not draw liquids without tips fitted on the tip cones.
- Do not lay down pipettor with tips filled on the pipettor
cones.
- Do not draw volumes of liquid exceeding the pipet-
tor's range.
- Be sure that tips are fitted properly.
- During operation, the pipettor must be held vertically,
tips should be immersed in liquid to a depth of 2 to 4 mm.
ENGLISH
™
Pipettor.
™
Pipettor
4