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Calibration of MIcropipettes

1.0 PURPOSE

The purpose of the standard operating procedure is to provide guidelines for calibration of various range micropipettes

2.0 SCOPE

The scope of this standard operating procedure includes calibration of micropipettes.

3.0 RESPONSIBILITY

3.1 Q.A. Executive

3.2 Technical Manager

3.3 Q.A. Manager

4.0 REQUIREMENTS

4.1 Purified Water

4.2 Calibrated digital Balance

4.3 Micropipette with tips

4.4 Micropipette Manual

5.0 PROCEDURE

5.1 Performance Verification of a Micropipette

5.1.1 Micropipette performance is evaluated using Gravimetric method. In Gravimetric Method desired volume of purified
water is placed or dispensed from micropipette & checked in term of weight on calibrated digital balance. The desired volume is termed as Nominal volume.

5.1.2 Calculation is performed to convert the weight of water to volume or vice –versa.

5.1.3 If the volume measuring device is properly operated, then the nominal volume will be identical to the volume as calculated
from the weight of the water.

5.2 Calibration Procedure

5.2.1 Label 5 centrifuge tubes, Weigh each of them.

5.2.2 Use Micropipette of any size whichever is required for calibration, pipette the lower volume of that micropipette & aspired into the centrifuge tubes with the single tip.

5.2.3 Weigh each of the five tubes. By subtraction, determine the weight of water in each tube.

5.2.4 A calculation is performed to convert the weight of water to volume or vice –versa.

V = ————–

Where W = weight in mg

V = Nominal Volume in micro litre

D = density of purified water in mg/micro litre

5.2.5 Calculate the standard deviation (repeatability) of micropipette based on these five weights.

5.2.6 Determine the closeness of average weight of purified water is to the expected Weight. Example If we are using 5µL micropipette, the average weight to be 5 mg.

5.2.7 Determine the accuracy of the micropipette by percentage error.

5.2.8 Repeat all the above steps with two mid ranges of the micropipette.

5.2.9 Repeat all the above steps with single upper range of the micropipette

CLASS RESULTS: MICROPIPETTORS
Sr.No	Volume	Precision (expressed as Standard deviation)	Accuracy (relative per cent)	Measured Accuracy as per Instrument Specification	Measured CV %

5.3 Warning & Precautions

5.3.1 Never drop a micropipette.

5.3.2 Never rotate the volume adjuster of an the micropipette beyond the upper or lower range of the Instrument.

5.3.3 Never pass a micropipette through a flame.

5.3.4 Never use a micropipette without a tip thus allowing liquid to contaminate the shaft assembly.

5.3.5 Never lay a filled micropipette on its side thus allowing liquid to contaminate the shaft assembly.

5.3.6 Never immerse the barrel of a micropipette in liquid, only immerse the tip.

5.3.7 Never allow the plunger to snap up when liquid is being aspirated.

5.3.8 Store micropipette set to their highest volume. This releases pressure on the spring inside the micropipette

6.0 REFERENCE

6.1 The Biotechnology Project Laboratory Exercise 3 Measuring Volume.

FAQs

How often should I calibrate MIcropipettes?
- The frequency of calibration depends on factors such as usage frequency, type of samples, and environmental conditions. It is generally recommended to calibrate micropipettes regularly, typically every three to six months or after significant changes in usage patterns.
What are the consequences of not calibrating a micropipette?
- Failure to calibrate a micropipette can result in inaccurate volume delivery, leading to errors in experimental results, wasted reagents, and compromised data quality.
Can I calibrate of micropipette myself?
- Calibration of micropipettes requires specialized equipment and expertise. It is recommended to have micropipettes calibrated by trained professionals or using certified calibration services.
How can I verify the calibration of micropipette?
- Calibration of micropipettes can be verified by comparing the delivered volume to a reference standard or using a secondary calibration method, such as gravimetric or spectrophotometric analysis.
Are there any alternatives to manual Calibration of MIcropipettes?
- Automated calibration systems offer an alternative to manual calibration, providing increased efficiency, consistency, and traceability. However, they require proper validation and maintenance to ensure accuracy and reliability.