Dense And Viscous Liquids; Htl Pipette Tips; Recommendations - HTL Optipette OP2 Manual De Instrucciones

5 - DENSE AND VISCOUS LIQUIDS

The OPTIPETTE specifications of accuracy and preci-
sion 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 gravimetrically checked compensation of the volume
setting. Normally the degree of error resulting from heavy
or viscous liquids is negligible if the pipetting is done
slowly and carefully. It is most important to give the liq-
uids some time to follow the change of pressure by hold-
ing the pipette tip in its position for at least 2 sec. after
the aspiration and the blow out stroke.
If in extreme cases this method of operation does not
result in accurate values, a compensation could be
achieved as follows:
Weigh the liquid pipetted when the OPTIPETTE is set to
the nominal value. Then calculate the set-off from the
nominal value:
Corr: val. = 2 x nom. val. -
m - weight of the sample
γ
- density of liquid
Check this operation once again and correct if neces-
sary. Note the corrected value for further pipetting the
same kind of liquid.

6 - HTL PIPETTE TIPS

HTL tips are made from high performance polypropylene
and their quality guarantees the precision and accuracy
associated with the OPTIPETTE. Strict control is main-
tained throug hout the manufacturing process to ensure
the highest quality.
The accuracy and precision figures for the OPTIPETTE
are only guaranteed when HTL tips are used. The use of
inferior quality tips will seriously degrade the perfor-
mance of the OPTIPETTE.
Tips 10
These tips are used for volumes between 0.1 μl and 10 μl.
They are used with the OP2 and OP10 models.
Tips 200
These tips are used for volumes between 2 μl and 200 μl.
They are used with the OP20, OP50, OP100 and OP200
models.
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m
-
γ
Tips 300
These tips are used for volumes between 50 μl and 250 μl.
They are used with the OP250 models.
Tips 1000
These tips are used for volumes between 100 μl and
1000 μl. They are used with the OP1000 models.
Tips 5000
These tips are used for volumes between 500 μl and
5000 μl. They are used with the OP5000 models.
Tips 10000
These tips are used for volumes between 1000 and
10000 μl. They are used with the OP10000 models,
which are equipped with a white pushbutton.

7 - RECOMMENDATIONS

Observing the following recommendations will ensure
maximal possible accuracy and precision of liquid sam-
pling.
• Make sure to operate the OPTIPETTE slowly and
smoothly.
• The depth of immersion in the sample liquid should be
the minimum necessary and should remain constant
during aspiration.
• The OPTIPETTE should be held in a vertical position.
• Change the tip when volume setting is chan ged or when
a different liquid is to be aspirated.
• Change the tip if a droplet remains on the end of the tip
from the previous pipetting operation.
• Each new tip should be pre-rinsed with the liquid to be
pipetted.
• Liquid should never enter the OPTIPETTE shaft. To
prevent this:
- Press and release the pushbutton slowly and smoothly.
- Never turn the pipette upside down.
- Never lay the pipette on its side when there is liquid in
the tip.
• Never force the volume setting beyond its recommended
limits.
• When pipetting liquids with temperatures different from
the ambient temperature, it is reco mmended to pre-
rinse the tip several times before use.
• Do not pipette liquids with temperatures above 70°C.
ENGLISH
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