Five Things You Should Know about the New Pipette Calibration ISO 8655:2022

In April 2022, the ISO 8655 guidelines made several changes to the calibration and testing requirements for pipettes. These updates affect general users as well as labs that work in compliance, such as manufacturing or calibration labs. We’re breaking down all these updates for you with the help of our in-house experts.  
 

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1. What is the ISO 8655 standard?
 

Pipettes are used daily to prepare samples, controls, and assay reagents in the research laboratory. Since pipettes touch virtually every experiment, pipetting accuracy is extremely important. ISO 8655 is an international standard for the calibration and testing of pipettes and other piston-operated volumetric apparatus (POVA), like burettes, dilutors, dispensers, and syringes.  
 

2. The new ISO 8655:2022 has nine parts  

The ISO 8655:2022 for pipette calibration has nine parts; that’s two more than the previous version. Below is a list of parts in the new ISO: 
 

• Part 1: Terminology, general requirements, and user recommendations 
• Part 2: Pipettes 
• Part 3: Burettes 
• Part 4: Dilutors 
• Part 5: Dispensers 
• Part 6: Gravimetric reference measurement procedure for the determination of volume 
• Part 7: Alternative measurement procedures for the determination of volume 
• Part 8: Photometric reference measurement procedure for the determination of volume 
• Part 9: Manually operated precision laboratory syringes 

3. Stricter language about pipettes: Part 2
 

ISO 8655 Part 2 specifies maximum permissible errors for pipettes, requirements for markings, and the information manufacturers must provide. “Part 2 includes air-displacement and positive displacement pipettes, multi-channel and single-channel variants,” explains Joni Åke, Product Manager at Sartorius. “Importantly, the new ISO always combines the tip and the instrument as one system.” 
 

Pipette tips 
 

• Pipette tip manufacturers must prove that the system (pipette + tip) fulfills all requirements and maximum permissible errors.  
• To account for variation in manufacturing, the tip must be changed at least once per volume tested during calibration. 
• Tips are single use, so you can only mount the tips once. 
• Multi-channel pipette tips have new maximum tolerances for how bent the tips can be, especially tips less than 100 μL in volume.  

Maximum permissible errors 
 

• There are additional maximum permissible error limits for 100% (the nominal volume), 50%, and 10%. 

User information 
 

• Both pipette and tip manufacturers must disclose which pipette and tip combinations fulfill the ISO 8655 standards. 

4. Pipette testing and calibration: Part 6, Part 7, and Part 8
  

Calibration sets the foundation for reliable and reproducible pipetting. Prior to the update, gravimetric measurement was the gold standard for calibration and testing. According to the new ISO 8655:2022, it’s ok to use either a gravimetric procedure (Part 6), or a photometric procedure (Part 8). 

Part 7 addresses the strict environmental requirements for testing and calibration. “It is not always possible to fulfill these, especially when calibrating or testing on a customer site,” says Axel Taube, Service Product Manager at Sartorius. “Alternative measurement procedures described in Part 7 allow deviations from these requirements within defined limits, and alternative gravimetric measurements can also be performed according to Part 7 A.2.”
  

5. You will need higher precision balances
 

The new ISO has requirements on the readability, the repeatability and the so called "expanded uncertainty in use" for balances that are used for pipette calibration and testing. Per the new ISO 8655 standards, some labs may need to upgrade their balances. “A six-place balance is now needed for pipettes with nominal volumes smaller than 20 µL, and precision balances for volumes between 20 µL and 199 µL”, explains Axel.  

Further, measuring multi-channel pipettes in parallel is now specifically mentioned in the new ISO. To keep up to this, we recommend a balance with several weighing cells, such as the SpeedCal Calibration System by Sartorius that can calibrate multi-channel pipettes of up to 12 channels in parallel.

Learn how Sartorius’ pipette calibration solutions can help you achieve compliance, efficiency, and lower costs. Read our ISO 8655:2022 FAQs for more in-depth information about the new standards.