5 - DENSE AND VISCOUS LIQUIDS
For moderately dense or viscous liquids, compensation
is possible by setting the volumeter higher than the
re qu ired value.
For liquids, which are less, dense than water, compensation
is possible by setting the volume ter lower than the re qu ired
value.
Example: to transfer 10 μl of serum using VWR
Signature
™
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 Signature
Strict control is maintained throughout the manufacturing
process to ensure the highest quality.
The accuracy and precision figures for the VWR
Signature
™
Pipettor are only guaranteed when VWR
tips are used. The use of inferior quality tips will seriously
degrade the performance of the VWR Signature
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.
7
™
Pipettor.
™
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 between 1000 and 10000 μl.
They are used with the VWR VE10000/V10000 model.
7 - RECOMMENDATIONS
The recommendations below will ensure maximum
accu ra cy and precision from your VWR Signature
Pipettor.
• When pipetting, the VWR Signature
have the volume setting locked with the locking ring in
the upper position.
• Make sure to operate the VWR Signature
slowly and smoothly.
• The depth of immersion in the sample liquid should be
the minimum necessary and should remain constant
during aspiration.
• The VWR Signature
™
ver ti cal 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 Signature
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
ENGLISH
™
Pipettor should
™
Pipettor
Pipettor should be held in a
™
Pipettor
™
8