Micropipettes: Types, Volume Ranges, and How to Choose the Right One

Short answer: a micropipette transfers microlitre volumes (about 0.1–1000 µL) by displacing air or liquid through a disposable tip. Which one you need is set by your volume, the liquid, and your throughput — and the tip is part of the calibrated system, not an accessory. Pick the smallest pipette that covers your volume, match the mechanism to the liquid, and recalibrate when you change tip type.

Pick by the job, not by habit

  • 0.5–10 µL, PCR / qPCR master mixes
    P10 (single-channel)
    Small range = accuracy where it matters; minimises carryover
  • 20–200 µL routine aliquoting
    P200 (single-channel)
    Covers the most common bench volumes in its accurate mid-range
  • 200–1000 µL reagent / buffer transfer
    P1000 (single-channel)
    Right range for larger transfers; avoid using a P200 over-extended
  • Loading 96-well plates
    8- or 12-channel pipette
    Parallel dispensing cuts time and improves row-to-row consistency
  • Volatile, viscous or dense liquids (DMSO, glycerol, acids)
    Positive-displacement pipette
    No air cushion = no density/vapour error on difficult liquids
  • High-throughput repetitive dispensing
    Electronic / repeater pipette
    Reduces hand strain and operator-to-operator variation

Burette vs pipette, side by side

  • Mechanism
    Air cushion between piston and sample
    Piston contacts liquid directly — no air gap
  • Best for
    Aqueous buffers, everyday solutions
    Volatile, viscous, dense or foaming liquids
  • Tip type
    Standard disposable tips
    Dedicated capillary-piston tips
  • Accuracy risk
    Error on non-aqueous / hot / cold liquids
    Higher consumable cost per sample
  • Cross-contamination
    Use filter tips to protect the shaft
    Piston-tip is single-use by design
  • Typical cost
    Lower; broad tip ecosystem
    Higher; specialised tips required

Pick the smallest pipette that covers your volume

Accuracy is best in the top third of a pipette's range and worst near the bottom. A P200 set to 20 µL is less reliable than a P20 set to the same 20 µL. So when a volume sits at the edge of two pipettes, choose the smaller one — you trade a little reach for real accuracy.

Air-displacement vs positive-displacement

Most lab micropipettes are air-displacement: an air cushion sits between the piston and the sample, calibrated for aqueous solutions at standard conditions. They are fast and accurate for everyday buffers. Positive-displacement pipettes move a piston in direct contact with the liquid, eliminating the air cushion error for liquids that are volatile, viscous, or dense (DMSO, glycerol, concentrated acids). Using an air-displacement pipette on those liquids quietly under- or over-delivers every time.

The tip is part of the calibrated system

Under ISO 8655, the pipette and its tip are calibrated together as one unit. Three consequences people miss: changing tip brand or type can shift accuracy and warrants a recalibration check; pre-wetting the tip (aspirate and expel once before the real draw) stabilises the air cushion; and a poorly sealed or wrong-size tip is a more common accuracy problem than the pipette mechanism itself.

Standards

  • ISO 8655:2022
    Piston-operated volumetric apparatus; pipette + tip as one calibrated system
  • ISO 8655-2
    Defines systematic (accuracy) and random (precision) error limits by volume
  • Calibration interval
    Typically every 3–12 months, or after changing tip type or brand

Frequently asked questions

  • What volume range does a micropipette cover?
    Common single-channel models span about 0.1–1000 µL across P2/P10/P20/P200/P1000; pick the one whose mid-range matches your volume.
  • Air-displacement or positive-displacement — which do I need?
    Air-displacement for normal aqueous work; positive-displacement for volatile, viscous or dense liquids where the air cushion causes systematic error.
  • Do I need to recalibrate if I change tip brand?
    Run a check. Under ISO 8655 the tip is part of the calibrated system, so a different tip type can shift accuracy outside spec.
  • Single-channel or multichannel?
    Single-channel for general bench work; 8- or 12-channel when loading plates and parallel, consistent dispensing matters.
Need tips that match your pipette? See the pipette-tips selection guide, or contact us for factory-direct supply.