D-806

Use of a Mechanical Pipette

Section D — Laboratory Operations and Specifications Revision 1 6 pages

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1.0 Purpose

The purpose of this procedure is to describe the proper use of mechanical pipettes in the QC

Laboratory along with instructions on how to ensure the mechanical pipette is functioning

properly prior to use.

2.0 Scope

This procedure provides specific instructions for use of all mechanical pipettes in the QC

Laboratory.

3.0 Responsibility

3.1 QC Laboratory personnel are responsible for the application and compliance of this

procedure.

3.2 QC Laboratory Management is responsible for the execution of and compliance to this

procedure.

3.3. QC Laboratory Management is responsible for keeping this procedure current with

latest Ion Labs practices.

4.0 Definitions

4.1 OC — Quality Control

42 Mechanical Pipette — laboratory tool used to transfer a precise and accurate volume of

liquid. Mechanical pipettes are typically used when a low volume of liquid is
transferred, usually at the pl level. These pipettes are offered in various volume sizes,

both fixed and adjustable.

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Standard Operating Procedure SOP No | Rev
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Use of a Mechanical Pipette

4.3. Positive Displacement Pipette - used to accurately pipette very viscous, volatile, hot or

cold, or corrosive samples. Pipette tips for these pipettes contain a piston to aid in

volume transfer.

5.0 References

N/A

6.0 Procedure

Note: a mechanical pipette should be used when a small volume of liquid is to be transferred

(less than 2mL), the liquid is viscous, or the liquid is corrosive.

6.1 Use of Mechanical Pipette

Selecting a mechanical pipette should consider the following:
6.51 6.1.1.1 Volume of liquid to be transferred

6.1.1.2 Composition of liquid to be transferred

6.1.1.3. The calibrated range of the pipette

Choose appropriate pipette tip for the mechanical pipette and attach.

If various volume pipette, set to the volume amount to be transferred. If fixed
6.1.3 volume pipette this step is not necessary.

6.1.4 Depress the plunger.

Pre-wet tip by immersing the tip to the correct depth, which can vary by the
6:15
pipette and tip, and smoothly let the plunger go to its resting position.

Wait about one second for the liquid to flow into the tip. Discard liquid.
6.1.6

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Standard Operating Procedure SOP No Rev oe
Use of a Mechanical Pipette
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6.1.7 Repeat steps 6.1.5-6.1.6 with the exception of discarding liquid. Place the

pipette—held at 10-45 degrees—against the wall of the receiving chamber, and

smoothly depress the plunger to the first stop.

6.1.8 Wait one second and then depress the plunger to the second stop.

6.1.9 Slide the tip up the vessel wall to remove the pipette.

6.1.10 Allow the plunger to return to its rest position.

6.1.11 If transfer complete, eject tip from pipette.

Note: Do NOT allow any mechanical pipette to lay on its side with a previously used

attached tip. Doing this will allow any residual liquid to potentially contaminate
the inside mechanics of the pipette, causing corrosion and/ or damage to the

pipette.

6.2 Weekly pipette check

6.2.1 Each pipette requires an at time of use check performed weekly prior to its use.

6.2.2 Results will be documented in a laboratory notebook for each pipette evaluated.

6.2.3. Materials needed: Balance, DI Water, thermometer, pipette and pipette tips.

6.2.4 At Time of Use Evaluation:

6.2.4.1 Leak Test (Step 1)

e Pre-wet tip as outlined in section 6.1.5.

e Using the same tip, aspirate the nominal volume.

e With the full tip immersed approximately 2mm in liquid, hold

pipette vertically for 30 seconds.

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Standard Operating Procedure SOP No | Rev
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Use of a Mechanical Pipette

If liquid level does not drop proceed with step 2. If liquid level

drops, a leak is indicated and the pipette may require repair and/

or service.

6.2.4.2 Gravimetric Measurement (Step 2)

Acclimate DI Water and all supplies to room temperature.

Measure temperature of DI Water and record.

Place receiving container on balance and tare. For a more
accurate assessment, receiving container should be tared already

containing some DI Water.

Perform measurements at 100% and 10% of pipette volume

capacity. Transfer quantity of liquid to receiving container and

weigh, making sure to pre-wet tip as described in section 6.1.5.
Ensure to dispense along the inner container wall and finish by

drawing the tip end along wall to remove residual liquid. Record
weight in logbook. Repeat for a total of five measurements.

Convert weight to volume using density as outlined in Table 1.

Values observed should be evaluated against allowable deviation
as outlined in Table 2. In notebook indicate a pass or fail for

each pipette evaluated.

If at any time a mechanical pipette does not meet the criteria

outlined in Table 2, the pipette should be removed from service

and replaced or sent out for repair.

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U S s ta e n o d f a rd a M O e p c e h r a a n ti i n c g a l Pr P o i c p e e d t u t r e e S D O - P 8 0 N 6 o Re 1 v = age 5 of6

0 0.99987 18 0.99862 38 0.99299

3.98 1.00000 20 0.99823 40 0.99224

5 0.99999 25 0.99707 45 0.99025

10 0:99973 30 0.99567 50 0.98807

15 0.99913 35 0.99406 a2 0.98573

Table 2. Maximum Permissible Deviation

1-1000
1001-10,000 6 0.6

6.3 Example: If evaluating a 1000uL pipette, the below conditions must be met:

6.3.1 Acceptable Range for 100pL: 92-108pL

6.3.2 Acceptable Range for 1000pL: 992-1008uL

7.0 Calibration

7.1. Mechanical pipettes should be calibrated every 6 months.

7.2 Calibration should include cleaning, precision, and accuracy evaluation. Evaluations

are typically performed “as found” and “as left” so that confirmation of pipette
performance as found can be demonstrated.

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Standard Operating Procedure SOP No Rev
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D-806
Use of a Mechanical Pipette
If the mechanical pipette fails evaluation “as found” then an investigation into its use
bd
may need to occur and any potential impact assessment performed. The weekly pipette
checks as described in section 6.2 should capture any potential failures in real time.

8.0 Revision History

| Rev | Date | Description of Changes | CCR # | By |
|-----|----------|------------------------|-------|----|
| 0 | 06/15/21 | New 10/17/22 Revised allowable ranges, adopted calibration limits. Minor edits. CC-22-0411 J. Sassman | - | - |