Following the steps below you can be sure to follow the right pipetting techniques and avoid uncertain results.
1. Clean and check your pipette daily
A contamination-free pipette ensures
accuracy, so it’s important to clean the
pipette before and after every use.
2. Know proper pipetting techniques
- Pre-wet the pipette tip - Hold the pipette vertically when
drawing the liquid - Immerse the tip slightly into the
liquid during aspiration - Hold the pipette 45-degree angle
while dispensing - Touch off the pipette tip on the side
wall of the container
3. Use the appropriate pipette
It‘s essential to use a pipette with a maximum volume closest to the volume
you plan to aspirate and dispense. The
accuracy of your test will improve if the
volume used is close to the nominal
volume.
Example: If you need to dispense 20μL,
a 200μL pipette would be less precise
compared to a 20μL pipette which would
be ideal.
4. Use perfectly fitting pipette tips
Select pipette tips that have a perfect fit
and leak-tight sealing with your pipette
in order to have accurate and reproducible results. Follow the pipette supplier‘s
instructions on the correct pipette tips
to form a good seal between the tip and tip
cone. Leaky or poor fitting tips can give up
to 50% error in the pipetted volume.
5. Let your pipette adjust to the environment
It is recommended that you allow your
pipette and all testing equipment
to adjust if they are exposed to new
conditions and temperatures. This way
there will be fewer environmental
variables affecting your results.
6. Take a break
If you find yourself in the midst of what
seems to be an endless test, take a break (if possible). When your mind, muscles,
and eyes are fresh, your results will show it;
fatigue can promote sloppiness and mistakes. If you are performing a time-sensitive test and can‘t take a break, remember
to maintain good posture and keep your
elbows in, and your arms out front.
The Do's and Don'ts of Pipette Storage and Handling
Do use a pipette stand for storage
Use a pipette stand to keep pipettes in
a vertical position in order to avoid
contamination, and to allow easy
tracking of the pipette’s location.
Do clean and decontaminate
pipettes before use
It’s not complicated. Simply wipe down
the exterior with a 70-per cent ethanol
especially the end of the shaft.
Don’t overwind beyond the
pipette’s volume range
Winding the pipette outside of the
pipette’s volume range can damage the
pipette. If you accidentally overwind
the pipette, check it to see if it
needs to be re-calibrated.
Do calibrate your pipettes every
6 to 12 months
Pipettes should be calibrated every six to
12 months, depending on the frequency
of use and your lab requirements. Check
the manufacturer‘s guide or your
auditing body to create an appropriate maintenance schedule, and ensure you communicate it to
everyone in your lab.
