Last reviewed: 18 October 2026.
Most pipetting errors are blamed on the pipette, but the tip and the technique decide much of the result. This guide covers how to choose pipette tips (volume range, fit, filter, retention, sterility and packaging), the handling habits that keep volumes accurate, and how pipettes are calibrated under ISO 8655.
Key points
- Choose the smallest tip whose range covers your volume; a tip rated for the pipette’s full range gives the best seal and accuracy.
- “Universal fit” describes a tip designed to seat on most standard pipette shafts; it does not guarantee a perfect seal on every model, so check fit on your own pipettes.
- Filter (aerosol-barrier) tips protect the pipette shaft and the next sample from aerosols; use them for PCR set-up, nucleic acids, radioactive or infectious material.
- Low-retention tips reduce liquid left on the tip wall; they help with detergents, proteins, enzymes and viscous master mixes.
- Sterile, racked tips suit cell culture and molecular work; nonsterile bulk tips are cost-effective for routine aqueous work or in-lab racking and autoclaving.
- Pre-wetting the tip, holding the pipette vertically, aspirating slowly and using reverse pipetting for viscous liquids all reduce error.
- ISO 8655 is the international standard for piston-operated volumetric apparatus; Part 6 describes the gravimetric reference method used for calibration.
- The 2022 edition requires at least 3×10 gravimetric measurements and a tip change after every five dispenses during calibration.
- During ISO 8655-6 testing, room temperature should stay within ±0.5 °C and the water–air temperature difference within ±0.5 °C.
- For a 1000 µL pipette at nominal volume, ISO 8655-2 limits are ±8.0 µL systematic error and 3.0 µL random error; for a 200 µL pipette, ±1.6 µL and 0.6 µL.
How do I choose the right pipette tip?
Work through six questions in order:
- Volume range. Match the tip to the pipette: 0.1–10 µL (microvolume), 1–200 µL, 100–1000 µL, and larger formats for 5–10 mL pipettes. Tip colour (natural, yellow, blue) is a convention, not a specification.
- Fit. Universal-fit tips seat on most standard shafts. Some pipettes need brand-specific tips. A good fit seals with light pressure and ejects cleanly; banging or rocking the tip on is a sign of poor fit and distorts the tip.
- Filter or no filter. Use filter tips whenever carry-over would ruin the experiment: PCR and qPCR set-up, RNA work, infectious or radioactive samples. Standard tips are fine for buffers and routine reagents.
- Retention. Low-retention tips leave less liquid behind with detergent-containing buffers, protein solutions and enzymes, which matters when you pipette small volumes of expensive reagents.
- Sterility and certification. Cell culture needs sterile tips. For RNA work choose tips certified free of RNase and DNase. Nonsterile tips can be racked and autoclaved in-house.
- Packaging. Racked tips are convenient and sterile; bulk bags cost less per tip and suit high-throughput routine work.
Corning pipette tips by volume
| Volume | Catalog # | Format | Typical use |
|---|---|---|---|
| 0.2–10 µL | Corning 4840 | Microvolume, natural, bulk, nonsterile | Small-volume work, in-lab racking |
| 1–200 µL | Corning 4860 | Universal fit, yellow, racked, sterile | Sterile routine small volumes |
| 1–200 µL | Corning 4844 | Universal fit, natural, bulk, nonsterile | Routine 200 µL work, in-lab racking |
| 100–1000 µL | Corning 4714 | Universal fit, blue, hinged rack, sterile | Media and reagent aliquots |
| 100–1000 µL | Corning 4868 | Universal fit, blue, bulk, nonsterile | Routine 1 mL work |
These five catalog numbers are standard (non-filter) tips. For filter or low-retention formats, send your pipette model and volume and we will match a Corning catalog number: request a quote.
Which pipetting habits improve accuracy?
- Pre-wet the tip by aspirating and dispensing the liquid a few times before the measured stroke; this equilibrates humidity inside the tip and reduces evaporation loss.
- Hold the pipette vertically while aspirating and immerse the tip just below the surface, not deep into the liquid.
- Aspirate and dispense slowly and smoothly; release the plunger steadily rather than letting it snap back.
- Use reverse pipetting for viscous, foaming or volatile liquids: press to the second stop to aspirate, dispense to the first stop, and discard the remainder.
- Let pipette, tips and liquids reach room temperature before work; warm hands and cold reagents change the delivered volume.
- Change the tip between samples and reagents, and whenever liquid touches the outside of the tip.
How is a pipette calibrated under ISO 8655?
ISO 8655 covers piston-operated volumetric apparatus. Part 2 sets the maximum permissible errors for piston pipettes, and Part 6 describes the gravimetric reference method: dispensed water is weighed on a suitable analytical balance, the mass is converted to volume using a correction for water density and air buoyancy (the Z factor), and the mean and spread of the results give the systematic and random error.
The 2022 edition tightened the procedure. Key requirements include:
- A minimum of 3×10 measurements, at test volumes of 100%, 50% and 10% of nominal volume.
- Changing the tip after every five dispenses, so a 3×10 single-channel calibration uses six tips.
- Room temperature stable within ±0.5 °C and a water–air temperature difference no greater than ±0.5 °C, with water temperature recorded at the start and end.
- A balance whose readability and repeatability match the test volume (finer for smaller volumes).
- New routine tests between calibrations to catch problems early.
What are the ISO 8655 error limits?
| Nominal volume | Max. systematic error | Max. random error |
|---|---|---|
| 1000 µL | ±8.0 µL (±0.8%) | 3.0 µL (0.3%) |
| 200 µL | ±1.6 µL (±0.8%) | 0.6 µL (0.3%) |
Limits for other volumes and for settings below nominal volume are defined in ISO 8655-2:2022, which expresses them as relative errors. Use the current text of the standard, or your pipette manufacturer’s specification sheet, for any volume not listed here.
How often should pipettes be calibrated?
ISO 8655 does not fix a single interval. Labs set it from risk and use: how often the pipette is used, how critical the results are, the liquids handled, and the history of previous calibrations. Many labs combine a scheduled full calibration with the quick routine tests introduced in the 2022 edition, and recheck any pipette that has been dropped, opened or serviced.
Common questions
- Can I autoclave nonsterile tips? Yes, polypropylene tips are commonly autoclaved in racks; follow the manufacturer’s instructions and let them dry before use.
- Do universal tips fit every pipette? They fit most standard shafts, but some pipettes need brand-specific tips. Test the seal and accuracy on your own pipettes.
- When are filter tips worth the extra cost? Whenever aerosol carry-over would compromise results or contaminate the pipette: PCR, RNA, infectious and radioactive work.
Sources
- ISO 8655-2:2022 Piston-operated volumetric apparatus — Part 2: Pipettes. International Organization for Standardization. iso.org
- ISO 8655-6:2022 Piston-operated volumetric apparatus — Part 6: Gravimetric reference measurement procedure for the determination of volume. iso.org
- Mettler-Toledo Rainin. ISO 8655 updates: primary changes with ISO 8655:2022. mt.com
- Troemner. Pipette Standards Handbook (ISO 8655 maximum permissible errors). PDF
- Corning Life Sciences. Pipet tips and accessories. corning.com
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