How to Choose Pipette Tips: Types, Fit, and When to Use Filter Tips

Short answer: the tip is part of the calibrated pipette system — not an accessory. The wrong tip type, a poor seal, or a different brand can shift accuracy outside Class A limits without the pipette changing at all. Choose tips that fit your pipette model, match the liquid properties, and meet the contamination requirements of the application. Filter tips are not optional for PCR, RNA work, or any application where aerosol contamination would ruin results.

Pick by the job, not by habit

  • PCR, qPCR, or any DNA amplification work
    Filter tips (aerosol barrier)
    One aerosol contaminates the barrel; all subsequent reactions at risk
  • RNA work, RT-PCR
    Filter tips, RNase-free certified
    RNase from previous samples destroys RNA; filter + certified RNase-free
  • Radioactive, toxic, or infectious samples
    Filter tips
    Filter prevents liquid and aerosol entering the barrel and the lab air
  • Protein solutions, serum, viscous liquids
    Low-retention tips + reverse pipetting
    Standard tips leave a film; low-retention reduces loss on sticky liquids
  • Wide-bore transfer (cells, beads, DNA fragments)
    Wide-bore tips
    Standard narrow tips shear cells and large molecules; wide bore is gentler
  • General aqueous, non-critical transfers
    Standard tips matching pipette model
    OEM or certified-compatible tips; check fit and seal before use

Burette vs pipette, side by side

  • Aerosol barrier
    No barrier — open shaft
    Porous filter stops aerosols and liquid
  • Accuracy impact
    Baseline; what pipette is calibrated for
    Minimal if filter does not restrict flow
  • Required for
    General, non-contamination-sensitive work
    PCR, RNA, radioactive, toxic, infectious
  • Cost per tip
    Lower
    Higher (2–5× standard)
  • Autoclavable
    Yes — standard protocol
    Yes — but check filter integrity after
  • DNase/RNase-free
    Available but not always certified
    Typically certified DNase/RNase-free

Why tip choice affects accuracy — the ISO 8655 system view

Under ISO 8655, a piston-operated pipette and its tip are one calibrated system. The air-cushion volume between the piston and the liquid surface depends on tip geometry — internal diameter, wall thickness, and length. Change the tip brand or type and you change the air-cushion, which changes the delivered volume. For non-critical work the difference is negligible. For regulated assays, standard preparation, or any work where the volume feeds a calculation, use the tip type the pipette was calibrated with — or recalibrate after switching.

Filter tips — when they are required, not optional

A filter tip has a porous polyethylene or similar barrier inside the tip shaft. It stops aerosols, liquid, and particles from entering the pipette barrel. Use filter tips whenever: (1) the sample is a template for PCR or qPCR — one aerosol contaminates the barrel and every subsequent reaction; (2) the liquid is radioactive, toxic, or infectious; (3) you are pipetting RNA — RNase contamination from a previous sample destroys RNA in the next. Standard tips are adequate for non-contamination-sensitive work.

Low-retention tips — when the liquid clings

Standard polypropylene tips leave a liquid film on their inner walls — visible as droplets after dispensing. For protein solutions, serum, viscous liquids, or any liquid that wets the tip surface, this film represents lost volume. Low-retention (hydrophobic surface) tips reduce the film dramatically. Combined with reverse pipetting technique, they give the best accuracy on sticky or viscous liquids. The cost per tip is higher; use them selectively where the film loss is significant relative to the volume.

Standards

  • ISO 8655:2022
    Pipette + tip as one calibrated system; tip change may require recalibration
  • ISO 8655-2
    Systematic and random error limits — basis for evaluating tip-change accuracy impact
  • ISO 8655-6
    Gravimetric test method — use to verify accuracy after switching tip type or brand

Frequently asked questions

  • Does the tip brand affect pipette accuracy?
    Yes. Under ISO 8655 the tip is part of the calibrated system. A different brand changes the air-cushion geometry and can shift accuracy outside Class A limits — without the pipette itself changing.
  • When do I need filter tips?
    For PCR, qPCR, RNA work, and any application where aerosol contamination from the barrel would ruin results or pose a safety risk. For general aqueous transfers, standard tips are adequate.
  • What are low-retention tips for?
    For liquids that leave a visible film on standard tip walls — proteins, serum, glycerol, DMSO. Low-retention (hydrophobic) tips reduce the film, improving accuracy on sticky or viscous liquids.
  • Can I use any tip with my pipette?
    Only tips that seal correctly on your pipette model. A loose fit causes air leaks and under-delivery; an overly tight fit can crack the tip or damage the shaft. Use OEM or verified-compatible tips.
Need tips in bulk — standard, filter, low-retention, or wide-bore? Contact us for factory-direct supply from ISO-certified manufacturers.