Setting The Volume; Method Of Pipetting; Recommendations - HTL Discovery Comfort DV8-10 Manual De Instrucciones

2 - SETTING THE VOLUME

The setting of the volume of the aspirated liquid can be
done either by the pipetting pushbutton knob (Fig. 1A2)
or by the adjustment knob (Fig. 1B). The volume adjust-
ment 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). The volume shown by the counter is
represented by three digits, which should be read from
top to bottom. Typical meter readings are shown in the
following table:
Counter
Model
readings
—
| |
0
DV 8-10
—
| |
3
—
DV12-10
| |
5
—
—
| |
0
DV 8-50
—
| |
6
—
DV12-50
| |
5
—
—
| |
0
DV 8-200
—
| |
8
—
DV12-200
| |
5
—
—
| |
2
DV 8-300
—
| |
5
—
DV12-300
| |
0
—
To attain the maximum accuracy, set volume must be
approached from a higher value by diminishing counter
readings.
• If the desired volume is lower than set volume shown
by the counter, turn the pipetting pushbutton (Fig. 1A2)
or the black adjustment knob (Fig. 1B) to the direction
diminishing counter readings to the required volume.
Rotate the knob slowly and carefully to avoid passing
the setting value.
• If the desired volume is higher than set volume shown by
the counter, turn the pipetting pushbutton (Fig. 1A2) or
the 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 set-
ting 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
3
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
set from the higher value in the order of decreasing value.
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 cones of the multichannel mo dule, hold-
ing the pipette vertically and pressing it against the tips
in the rack box, until the shafts retreat about 1.5 mm. The
suspension system of the shafts ensures even and tight
sealing of tips. The rolling movement does not have to
be performed to seal the tips tightly. The liquid aspirated
into the tips should not flow out by gravity from properly
fixed tips. While holding the pipette 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
dispensing it out with slow and steady movement. Next,
still holding the pipette vertically, press the pipetting but-
ton until the first resistance point is felt, and immerse the
tips in the liquid to the depth of 2-4 mm, (Fig. 3B). Rele -
asing the pipetting button with a slow and uni form move-
ment 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 pipette should next be positioned at
an angle of 10-45 degrees in relation to inner walls of
destination vessels and tips should be emptied by press-
ing the pipetting button slowly until the first resistance
point is felt, (Fig. 3C). After a second, the pipetting button
should be pressed to the second resistance point in
order to expel remaining liquid, (Fig. 3D). Then 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,
(Fig. 3E). Finally, pressing the ejector button, detach the
tips. (Fig. 3F).

4 - RECOMMENDATIONS

To achieve maximum safety, precision and accuracy, the
following principles should be ob served:
• when pipetting, the pipette should have the volume set-
ting locked,
• do not draw liquids without tips fitted on the pipette
shafts,
ENGLISH
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