Aspirating And Dispensing Liquids; Pre-Rinsing - HTL Optipette OP2 Manual De Instrucciones

• If the desired volume is lower than set volume shown
by the counter, the operator should turn the or the
black adjustment knob (Fig. 1B) to the direction dimin-
ishing 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 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 OPTIPETTE
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
OP2
OP10
OP20, OP50, OP100
OP200, OP250, OP1000
OP5000
OP10000
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
when the pipetting pushbutton is rapidly released air
may enter the disposable tip.
5
Immersion depth (mm)
≤ 1
≤ 1
2 ÷ 3
2 ÷ 3
3 ÷ 6
5 ÷ 7
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.
Filters
Replaceable filter installed in a seat in the bottom part of
the shaft is used in 5000 μl and 10000 μl pipettes (Fig. 3L).
The filter prevents the aspirated liquid from entering into
the shaft and thus from polluting the inside of the shaft
and the piston. Using the filter is especially important
when aspirating and dispensing large volumes of liquid.
If the filter becomes wet during liquid aspiration it should
be replaced with a new one.

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 following
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.
ENGLISH
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