How to Autoclave Pipette Tips: Protocol, Boxes, and What to Check After

Most polypropylene pipette tips withstand standard autoclave conditions (121 °C, 15 psi, 15–20 minutes) without deforming — but only if the tips and boxes are autoclave-rated by the manufacturer, the cycle parameters are correct, and the tips are allowed to dry fully before use. Autoclaving wet tips introduces water into the pipette barrel and ruins accuracy on the first draw. Check the manufacturer specification before autoclaving any tip or rack.

Pick by the job, not by habit

  • Standard sterilisation of polypropylene tips
    Autoclave at 121 °C, 15 psi, 15–20 min
    Standard gravity cycle; confirm tips are autoclave-rated before use
  • Tips deforming or melting after autoclave
    Check cycle temperature and tip spec
    Dry-heat or >125 °C damages polypropylene; use liquid/gravity cycle only
  • Wet tips after autoclave cycle
    Extend drying phase; do not use wet tips
    Wet tips introduce water into barrel; accuracy lost for multiple draws
  • Filter tips needed after autoclaving
    Check filter integrity before use
    Autoclave can displace filter; verify disc is seated before pipetting
  • RNA or sensitive PCR work
    Use pre-certified tips from sealed pack
    Autoclaving re-introduces contaminants; factory certification is validated
  • Bulk tips, cost saving needed
    Refill insert systems (reload racks)
    Reload inserts allow autoclaving in original rack; lower cost per tip

Burette vs pipette, side by side

  • Sterility assurance
    Validated by manufacturer; traceable
    Dependent on in-house cycle validation
  • DNase/RNase-free
    Certified for as-supplied condition
    Not certified after autoclaving
  • Filter integrity
    Guaranteed in sealed packaging
    Must be checked after each cycle
  • Cost per tip
    Higher; individual packaging
    Lower; bulk tips autoclaved in rack
  • Best for
    PCR, RNA, regulated, critical assays
    General sterile work, non-PCR applications
  • Convenience
    Ready to use from pack
    Requires autoclave cycle + drying time

Standard autoclave protocol for pipette tips

Cycle: 121 °C, 15 psi (103 kPa), gravity or liquid cycle, 15–20 minutes sterilisation hold. Do not use dry-heat cycles — polypropylene softens above ~160 °C and tips will deform.

Loading: Keep tips in their original rack or box with the lid loosely closed or covered with autoclave tape and foil. Do not stack boxes more than two high — steam must circulate freely around all surfaces. Tips pointing down in the rack prevents pooling of condensate inside the tips.

Drying: After the cycle, open the autoclave door partially and allow a full drying phase (typically 20–30 minutes in the autoclave, or transfer to a 60 °C oven). Tips must be completely dry before use. A wet tip introduces a water plug into the air cushion — the first aspiration pulls water into the barrel rather than the sample, and accuracy is lost for multiple subsequent draws.

Filter tips after autoclaving — check the filter

Autoclaving can compress or shift the polyethylene filter inside a filter tip. After the cycle, hold a filter tip up to light and verify the filter disc is still seated centrally and intact. A displaced filter no longer stops aerosols reliably. For critical PCR or RNA work, use pre-sterilised tips from the manufacturer rather than autoclaving in-house — factory sterilisation is validated; in-house cycles are not.

When autoclaving is not the right choice

Tips certified DNase/RNase-free by the manufacturer are certified for the as-supplied condition. Autoclaving re-introduces potential contaminants from the autoclave chamber, water supply, and handling. For RNA work and sensitive PCR applications, use pre-certified tips directly from sealed packaging rather than autoclaving previously used or bulk-purchased tips.

Standards

  • 121 °C / 15 psi
    Standard autoclave conditions for polypropylene labware sterilisation
  • ISO 8655:2022
    Pipette + tip as calibrated system; tip condition after autoclaving affects accuracy
  • EN ISO 11135
    Sterilisation of health-care products — reference for sterility assurance validation

Frequently asked questions

  • Can pipette tips be autoclaved?
    Yes, if they are polypropylene and rated by the manufacturer. Use 121 °C, 15 psi, 15–20 minutes gravity cycle. Dry fully before use — wet tips introduce water into the pipette barrel and ruin accuracy.
  • Do filter tips survive autoclaving?
    Most do, but the filter can shift. After autoclaving, hold each tip to light and confirm the filter disc is still seated centrally. A displaced filter no longer stops aerosols reliably.
  • Should I autoclave tips for RNA work?
    No — use pre-certified DNase/RNase-free tips directly from sealed packaging. Autoclaving re-introduces potential contaminants from the autoclave chamber and water supply that factory certification eliminates.
  • Why are my tips deforming in the autoclave?
    The cycle temperature is too high or a dry-heat cycle is being used. Polypropylene softens above ~160 °C. Use a standard gravity or liquid cycle at 121 °C — never a dry-heat or flash sterilisation cycle for plastic tips.
Need autoclave-rated pipette tips or refill inserts at scale? Contact us for factory-direct supply from ISO-certified manufacturers.