SOP for Operation and Calibration of Micropipette

Standard Operating Procedure for Operation and Calibration of Micropipette.

1.0 Purpose: 
To lay down the procedure for operation and calibration of micropipette.

2.0 Scope:
This procedure is applicable for operation and calibration of all micropipettes.
pipette calibration

3.0 Responsibility:
Officer/ Designee Microbiology:
•To perform operation as per SOP.
•To perform calibration as per procedure and frequency.
•To fill calibration data sheet as per format.
Head/ Designee - Microbiology:
•To review, implement and ensure compliance of SOP.
Head/ Designee - QA :
•To approve, implement and ensure compliance of SOP.

4.0 Procedure:

4.1 Preliminary Check:

4.1.1 The pipette should be checked at the beginning of each day for dust and dirt on the surface of the pipette. If found unclean then clean with soft cloth duster. 

4.1.2 Check visually that tip cone of the pipette is not wet also check that there is no residue on tip cone if residue is observed or the tip cone of the  pipette is wet then use 70% IPA  for cleaning.

4.2 Operation:

4.2.1 Volume Setting: Volume can be changed continuously by rotating the setting ring.

4.2.2 Pipette Tips: The pipette can be sued only when a pipette tip is attached into which the liquid is aspirated.

4.2.3 Aspirating Liquid: The liquid, which is to be aspirated, is taken from a suitable vessel. Attach the tips to the pipette firmly. Immerse the pipette tips approximately 3-5 mm in to the liquid or into suitable depth into the liquid. Allow the setting button to slide back slowly. Pull the micropipette tips out of the liquid slowly.

4.2.4 Dispensing Liquid: Hold the tips at an angle against the inside wall of the tube/vial/bottle/suitable vessel. Press down the setting button slowly to the first stop and wait until the liquid stops flowing. Press down the setting button to the second stroke until the tip is completely empty. Hold down the setting button and pull the tips up the inner wall of the tube. Allow the setting button to slide back slowly.

4.3 Calibration:

4.3.1 Calibrate the micropipette in a vibration free room at a constant temperature of water between 20-25OC.

4.3.2 Calibration of micropipette should be done every 6 month ± 15 days with weight variation.

4.3.3 Different set of volumes should be taken performed.

4.3.4 Attached micropipette tips to micropipette and desired volume is set and water shall be aspirated.

4.3.5 Dispensed into dry beaker and weighed repeated for 10 times.

4.3.6 The mean of the weights are converted into µl using the following formula:
Volume = Weight of Water / Density of Water
(Density of Water at 20-25OC: 0.9982 mg/ µl : 1 mg/ µl) 

4.3.7 The percentage variation can be calculated by using following formula:
                                      Actual Weight - Observed Weight
Percentage Variation =-------------------------------------------X 100
                                                     Actual Weight
4.3.8 Perform the calibration by using set volumes.

4.3.9 Calibration Frequency: Calibration of micropipette should be done every 6 month ± 15 days.

4.3.10 Maintain the observation in format.

4.4 Handling, Care and Maintenance:

4.4.1 Do not lay down the pipette when a filled pipette tip is attached.

4.4.2 Avoid difference in temperature between pipettes and pipette tips as well 
as the liquid as this may lead to incorrect volumes being dispensed.

4.4.3 Do not allow any liquid to enter into the pipette.

4.4.4 Do not clean the pipette with acetone or aggressive solutions.