This document details the procedure for the operation and calibration of various variable range micropipettes. sop for cleaning operation and calibration of micropipette
It is the policy of Xyz Limited that a written procedure shall be followed for the Operation and Calibration of various variable ranges of Micropipettes and its use monitored in order to ensure smooth operation to obtain consistent and reproducible results and minimize downtime and meet regulatory requirements.
When:- This procedure is to be applied at the time of Operation and Calibration of various variable ranges of Micropipettes.
RESPONSIBILITY
Persons along with their responsibilities and accountability are
given below:
To prepare the SOP:- Executive – Corporate Quality Assurance
To follow the SOP accordingly:- Trainee Analyst/ Jr. Analyst/ Analyst/ Sr. Analyst
Manager – Quality Assurance:- To ensure implementation of SOP
PROCEDURE
5.1 GENERAL INSTRUCTIONS
5.1.1 Micropipettes
come in many sizes. The most commonly used micropipettes found in a lab are P-1, P-10,
P-20, P-50, P-100, P-200, P-250, P-1000, P-5000The number refers to the maximum
volume (measured in microliters) that can be transferred The Plunger button or
the body of the micropipette is marked
with the minimum and maximum volume range.
5.1.2 The micropipette functions by using a disposable plastic tip which is the only part of the micropipette that actually comes in contact with the solution.
5.1.3 The
tips come in various sizes and colors. Each size of micropipette uses a
specific size tip.
5.2 PRECAUTIONS
5.2.1 Avoid mishandling of micropipette.
5.2.2 Never rotate the volume adjuster of a micropipette beyond the upper or lower range because this will damage the micropipette.
5.2.3 Never pass a micropipette through flame/fuming chemicals or reagents.
5.2.4 Never use a micropipette without a tip thus allowing liquid to contaminate the shaft assembly.
5.2.5 Never
lay a filled micropipette on its side thus allowing liquid to contaminate the
shaft assembly.
5.2.6 Do
not contaminate the barrel of a
micropipette with the liquid, only immerse the tip.
5.2.7 Never
allow the plunger to snap up when liquid is being aspirated.
5.2.8 After
usage micropipette should be set to its highest volume as this releases pressure on the spring inside the micropipette
5.2.9 Perform
calibration by wearing gloves in hands.
5.3 OPERATION
5.3.1 Select
the correct size micropipette and tips.
5.3.2 Dial
the volume adjustment knob to set the proper volume in the digital volume
indicator.
5.3.3 Place
the tip tightly on the micropipette.
5.3.4 Hold
the micropipette vertically over the solution and push the plunger down to the
first stop.
5.3.5 Insert the tip into the solution.
5.3.6 Slowly release the plunger and note that the
solution is drawn into the tip.
5.3.7 Look at the tip to be sure that you do not
have bubbles in the tip. (if a bubble exists, expel the solution and try again.
5.3.8 Dispense the solution by touching the tip to the
side of the target container. Slowly depress the plunger to the second stop.
Before releasing the plunger, remove the tip from the target container.
5.3.9 Be sure the tip is empty, then use the tip ejector to dispose of the tip into an appropriate disposal container.
6.0 Calibration of Micropipettes
6.0.1 Calibration
Frequency: Half-Yearly
6.1 Requirements
6.1.1 Purified
Water
6.1.2 Calibrated
Digital Balance
6.1.3 Micropipette
with tips
6.2 Performance Verification of a Micropipette | Micropipette calibration frequency
6.2.1 Micropipette
performance is evaluated using the Gravimetric method. In Gravimetric
Method desired volume of purified water is placed or dispensed from the micropipette & checked in terms of weight on a calibrated digital balance. The desired volume is termed as volume
6.2.2 Calculation is performed to convert the weight of water to volume or vice–versa.
6.2.3 If the volume measuring device is properly operated, then the volume will be identical to the volume as calculated from the weight of the water.
6.2.4 Take wt in mg for the micropipette 10 µl or below 10 µl. For all other micropipettes take weight in gm.
6.2.3 Label
5 centrifuge tubes,
6.2.4 Mount
a new pipette tip & pre-rinse once with water.
6.2.5 Put
the 1.5ml microcentrifuge tube on the weighing balance.
6.2.6 Tare
the balance.
6.2.7 Add
the necessary volume of water using a micropipette in the microcentrifuge tube.
6.2.8 Record
the weight
6.2.9 Repeat
the procedure five times using five different tubes & record the weight in
the calibration data sheet.
6.3.0 Calculate
Average weight, Standard deviation & % CV.
6.3.1 Calculate
the volume of water using the formula:
Micropipette calibration calculation
V =
Wt / 0.99602
Where V = volume in µl or ml
W = Avg.wt in mg or gm.
0.99602
= density of water at 25˚ C
6.3.2Calculate the
percentage Accuracy (A %) using the formula :
A% = V
- VSET X 100
VSET
Where Vset = set volume
6.3.4 The above step should be followed at the Low, Mid, and High Points of the Micropipette for example a 100 µl pipette is taken then calibration has to be performed at 10 µl (Low), 50 µl (Mid) &100 µl ( High) points.
6.3.5 For a micropipette 10 µl or below only a high
point should be considered for calibration.
6.3.6 Record the Calibration data on XYZ/CQA/SOP-076/FR-01 as Calibration Datasheet Appendix I
7.0 GENERATION OF INSTRUMENT CALIBRATION
NUMBER
Generate the instrument calibration number on the calibration datasheet as INSCALXXYYZZZ where INS denotes instrument, CAL denotes calibration, XX denotes the year, YY denotes month and ZZZ denotes sequence number.
8.0 ABBREVIATION
XYZ Xyz Limited
SOP Standard Operating Procedure
QC Quality Control
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