Dense And Viscous Liquids; Vwr Pipettor Tips; Recommendations - VWR Signature EHP Manual Del Usuario

VWR EHP-03-2008 13 9-04-08

5 - DENSE AND VISCOUS LIQUIDS

For moderately dense or viscous liquids, compensation
is possible by setting the volumeter higher than the
required value.
For liquids, which are less, dense than water, compensa-
tion is possible by setting the volumeter lower than the re-
quired value.
Example: to transfer 10 μl of serum using VWR EHP
Pipettor, model VWR VE20/V20.
Set the volumeter to 10 μl. Aspirate a volume of liquid
and measure it gravimetrically. If the corresponding
volume is measured as 9.5 μl, the error is 0.5 μl. Increase
the volumeter setting by 0.5 μl to 10.5 μl and repeat the
measurement.
If the second measurement is not accurate enough,
adjust the volumeter up or down to take account of the
remaining error.
When dispensing dense or viscous liquids, wait one or
two seconds longer at the first stop before expelling the
residual liquid.

6 - VWR PIPETTOR TIPS

VWR tips are made from high performance polypropylene
and their quality guarantees the precision and accuracy
associated with the VWR EHP Pipettor.
Strict control is maintained throughout the manufacturing
process to ensure the highest quality.
The accuracy and precision figures for the VWR EHP
Pipettor are only guaranteed when VWR tips are used.
The use of inferior quality tips will seriously degrade the
performance of the VWR EHP Pipettor.
Tips 10
These tips are used for volumes between 0.1 μl and 10 μl.
They are used with the VWR VE2/V2 and the VWR
VE10/V10 models.
Tips 200
These tips are used for volumes between 2 μl and 200 μl.
They are used with the VWR VE20/V20, VWR VE50/V50,
VWR VE100/V100, VWR VE200/V200 models.
Tips 300
These tips are used for volumes between 50 μl and 250 μl.
They are used with the VWR VE250/V250 model.
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Tips 1000
These tips are used for volumes between 100 μl and
1000 μl. They are used with the VWR VE1000/V1000
model.
Tips 5000
These tips are used for volumes between 1000 μl and
5000 μl. They are used with the VWR VE5000/V5000
model.
Tips 10000
These tips are used for volumes betwen 1000 and 10000 μl.
They are used with the VWR VE10000/V10000 model.

7 - RECOMMENDATIONS

The recommendations below will ensure maximum accu-
racy and precision from your VWR EHP Pipettor.
• When pipetting, the VWR EHP Pipettor should have
the volume setting locked with the locking ring in the
upper position.
• Make sure to operate the VWR EHP Pipettor slowly
and smoothly.
• The depth of immersion in the sample liquid should be
the minimum necessary and should remain constant
during aspiration.
• The VWR EHP Pipettor should be held in a vertical
position.
• Change the tip when volume setting is changed 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 VWR EHP Pipettor shaft.
To prevent this:
- Press and release the pushbutton slowly and smoothly
- Never turn the pipettor upside down
- Never lay the pipettor on its side when there is liquid
in the tip.
• Never force the volumeter beyond its recommended
limits.
• When pipetting liquids with temperatures different from
the ambient temperature, it is recommended to pre-rinse
the tip several times before use.
ENGLISH
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