Pipetting Instructions (Jian)
Macro-Pipettes:
Ask for help if you need help.
Checked?
1 Never pipette by mouth
2 Use an appropriately sized pipette and pro-pipettor
Do not transfer an "extra" drop! (touch the tip of the pipette to the side of the
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container when filling)
Do not forget to transfer the "last" drop! (touch the tip of the pipette to the side of
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the container when emptying)
Micro-Pipettes:
Before using the micropipettes, read the instructions for their proper use:
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Use a clean micropipette tip. The same tip can be reused if re-pipetting from the
same solution.
Be sure the micropipette tip is sealed firmly on the end of the pipette.
Note: bare fingers are loaded with RNAse and oils, even if you just washed
them. Keep your fingers well away from the pipette filling tip, and don’t immerse
the part of the tip that you touch into your (clean) solution. Immerse only the tip
of the pipette tip into the sample that is being pipetted.
Fill the pipette slowly. Do not let the filling plunger snap back, or the sample will
aerate and adhere onto the upper part of the tip as separate drops which are very
hard to transfer. Note: viscous samples take much longer to fill (and discharge).
Check that the tip does not carry an extra drop when you remove the filled tip
from your solution. It is a good practice to gently touch the tip to the inside of the
container to remove any extra drop.
Be able to feel the difference in spring pressure between the fill and the blow-out
positions of the plunger.
Discharge the sample slowly. Discharging too quickly will leave part of the
sample adhering to the inside of the pipette. This is especially true for viscous
samples.
Be sure that the last part of a drop is transferred. It is a good practice to touch the
tip to the inside of the vessel to ensure that the last part of a drop is transferred.
Be sure you know how to adjust the volume of and read to calibration scales of
the variable micropipettes.
Check the calibration of the micropipette by weighing (on a water-resistant tare;
on a micro-balance) a measured volume of water. (The density of water at 20oC
is 0.9982071 grams/ml. Be aware that the weight of the water drop will change
as the water evaporates from the tare.)
Clean up when messed up (wipe with DI water).
Checked?
Select the Right Micro-Pipettes:
Volume range
Volume
Volume increment
Inaccuracy* Imprecision*
Dark Grey operating button, for use with 10 µl pipette tips
0.1–2.5 µl
±12.0%
≤6.0%
1.25 µl
±2.5%
≤1.5%
2.5 µl
±1.4%
≤0.7%
±2.5%
≤1.8%
5 µl
±1.5%
≤0.8%
10 µl
±1.0%
≤0.4%
±5.0%
≤1.5%
10 µl
±1.2%
≤0.6%
20 µl
±1.0%
≤0.3%
±3.0%
≤1.0%
50 µl
±1.0%
≤0.3%
100 µl
±0.8%
≤0.2%
±2.5%
≤0.7%
100 µl
±1.0%
≤0.3%
200 µl
±0.6%
≤0.2%
0.25 µl
0.002 µl
Gray operating button, for use with 20 µl pipette tips
0.5–10 µl
1 µl
0.01 µl
Yellow operating button, for use with 200 µl and 300 µl pipette tips
2–20 µl
10–100 µl
20–200 µl
2 µl
10 µl
20 µl
0.02 µl
0.1 µl
0.2 µl
Blue operating button, for use with 1,000 µl pipette tips
100–1,000 µl
±3.0%
≤0.6%
500 µl
±1.0%
≤0.2%
1,000 µl
±0.6%
≤0.2%
±2.4%
≤0.6%
2,500 µl
±1.2%
≤0.25%
5,000 µl
±0.6%
≤0.15%
±3.0%
≤0.6%
5 ml
±0.8%
≤0.2%
10 ml
±0.6%
≤0.15%
100 µl
0.1 µl
Violet operating button, for use with 5 ml pipette tips
500–5,000 µl
500 µl
5 µl
Turquoise operating button, for use with 10 ml pipette tips
1–10 ml
1 ml
10 µl
How to adjust Micro-Pipettes:
500-5000 uL
100-1000 uL
10-100 uL
0.5-10 uL
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0
3.750 ml
Note: 1 ml = 1000 ul
0.652 ml
0.087 ml
0.0072 ml