Micropipette Evaluation
Updated 1/26/2024 11:07 AM
Introduction
Materials
- dH2O
- Micropipettes
- + tips
- Weight Boats
- Digital balance
Procedure
- Fill up a clean beaker with dH2O
- Take one micropipette of each of the following: P-20, P-200 & P-1,000. (Any additional to be calibrated)
- Verify the Analytical Balance
a) Check that all the analytical balance's glass doors are closed.
b) Ensure that the analytical balance is balanced.
- Place a plastic weight boat for weighing on the analytical balance.
- Press the Zero (Tare) button.
- Attach the pipette tip to the micropipette by firmly pressing the micropipette into the tip’s cavity.
Just firmly press, DO NOT SMASH micropipette into the tip.
- Before using the micropipette, aspirate the maximum volume the micropipette can hold and discard the water into another container 5 times.
CRITICALThis allows the air volume's humidity to stabilize.
- Add the specified volume (maximum, medium, and lower limit) for each of the micropipettes.
- Download the template of the record tables: MICROPIPETTE_CALIBRATION_TBLS.pdf
- record the weight on a table.
- Press Zero (Tare) after each measurement to reset the balance back to zero.
- Make notes for each record table in the “observations” pane of the attached tables.
- Calculate the mean, standard deviation, and coeficcient of variation (%CV).
- Any micropipette with a %CV higher than 1% should be flagged for followup calibration by the technician.
Evaluate micropipette calibration status by constructing a volume table and determining mean pipette volume, standard deviation and coefficient of variation. Calculations can be done with Excel or R.