Follow
1.0 OBJECTIVE : To set up a standardized general procedure for the operation of micropipette.
2.0 SCOPE : This SOP is applicable for the operation of Micropipettes used in the quality control laboratory of Beximco Pharmaceutical Limited, Track-II.
3.0 RESPONSIBILITY
3.1 Operating personnel is responsible for carrying out the procedure.
3.2 Overall responsibility for training, implementation & follow-up with the QC Manager or his nominee.
4.0 ACCOUNTABILITY
4.1 Head of Quality.
5.0 PRECAUTIONS
5.1 Be careful to avoid dust and dirt on the outer surface of the pipette.
5.2 Particular attention should be paid to tip cone.
5.3 No other solvents except 70% IPA should be used for cleaning the pipette.
6.0 PROCEDURE
6.1 Setting of the delivery volume
6.1.1 Set the delivery volume using the operation button on the top of the pipette.
6.1.2 To increase the delivery volume, turn the operating button anticlockwise. To decrease turn it clockwise.
6.1.3 Ensure that the desired delivery volume clicks into place and the digits for the volume are completely visible on the handle display.
6.1.4 Do not set volume outside of the pipette’s specified volume range. If excessive force is used to turn the push button outside the range, it may jam the mechanism and eventually cause defects.
6.2 Pipetting techniques
6.2.1 For the best possible accuracy push and release the button slowly at all times, particularly when working with liquids having high viscosity. Never allow the operating button to snap back.
6.2.2 Ensure that a clean tip is firmly pushed on to the tip cone of the pipette and there are no foreign particles in the tip itself.
6.2.3 Wet the newly attached tip with the solution being pipetted before any actual pipetting takes place. This is done by filling and emptying the tip 2-3 times. Hold the pipette vertically during the liquid intake.
6.2.4 The temperature of the pipette tip should be equalized to that of the solution.
6.2.5 Forward technique: Depress the operating button to the first stop.
6.2.6 Dip the tip under the surface of the liquid to be taken about 1 cm deep and slowly release the operating button. Withdraw the tip from the liquid touching it against the edge of the reservoir to remove excess liquid.
6.2.7 Deliver the liquid by gently depressing the operating button to the first stop. After a delay of about one second, continue to depress the operating button all the way down to second stop. This action will empty the tip.
6.2.8 Release the operating button to the ready position again.
6.2.9 If necessary, change the tip and continue with the pipetting.
6.2.10 Reverse technique: The reverse technique is suitable for dispensing liquids having high viscosity or a tendency to foam easily. The technique is also recommended for dispensing very small volumes.
6.2.11 Depress the operating button all the way down to the second stop.
6.2.12 Dip the tip under the surface of the liquid to be taken about 1 cm deep and slowly release the operating button. This action will fill the tip. Withdraw the tip from the liquid touching it against the edge of the reservoir to remove excess liquid.
6.2.13 Deliver the preset volume by gently depressing the operating button to the first stop.
6.2.14 Hold the operating button at the first stop. Some liquid will remain in the tip and should not be included in the delivery.
6.2.15 The remaining liquid is either discarded with the tip or pipetted back into the stock container.
6.3 Operation of Digital Micropipette
6.3.1 Select the “PIPET MODE” by pressing MODE Option.
6.3.2 Reset the desire volume by pressing upper arrow keys and the down arrow keys. Press and hold the upper arrow keys to increase the volume and press and hold the down arrow keys to decrease the volume.
6.3.3 When the desired volume is set, attached a tip. Press the shaft into the end of the tip with only enough force to make a positive seal.
6.3.4 Immerse the tip end into the sample and touch either trigger to aspirate.
6.3.5 To dispense, touch the tip end against the vessel side wall and press either trigger.
6.3.6 Carryout the same procedure from 6.3.1 to 6.3.5 for repeat sampling.
6.4 Tip ejection
6.4.1 Each pipette is fitted with a tip ejector system to eliminate the risk of contamination. Direct the pipette towards a suitable waste receptacle and press tip ejector plunger with the thumb to dispose the tip safely.
