Laboratory micropipettes: how can microlitre volumes be pipetted accurately and reproducibly?

A mainstay of pipetting, the micropipette handles aspiration and dispensing of minute volumes, from 0.1 µL to several mL, with accuracy and repeatability compliant with ISO 8655. Whether air-displacement, positive-displacement, mechanical, electronic/motorised or dispenser, it delivers reliable transfers for molecular biology, microbiology, analytical chemistry and quality control. Compatibility with filter tips and low-retention tips, reduced operating forces, autoclavable parts and advanced modes (multi-dispense, mixing) help keep your day-to-day workflows safe.

What types of micropipettes are there, and how do you choose the right one?

The mechanical micropipette with air displacement is the most widely used: a piston creates an air cushion that moves the liquid. It excels with aqueous solutions and offers an excellent precision/robustness balance. Electronic micropipettes – also called motorised – automate aspiration/dispensing, reduce inter-operator variability and offer modes (pipette, multi-dispense, reverse, mix). The positive-displacement micropipette removes the air cushion thanks to a disposable piston in direct contact with the sample: ideal for viscous, volatile or foaming liquids. Finally, the dispenser micropipette (repetitive) delivers successive aliquots from a reservoir (syringe/graduated tip), perfect for long series and ELISA kits.

Selection criteria: volume range (e.g. 0.1–2 µL, 2–20 µL, 20–200 µL, 100–1000 µL, 1–10 mL), accuracy (±%), CV (repeatability), compatibility with filter/low-retention tips, ergonomics (operating force, tip ejection), autoclavable parts (121 °C), chemical resistance (PVDF, PBT). In practice: pre-wet the tip, pipette at a stable temperature, favour reverse pipetting for challenging liquids, and use filter tips to prevent aerosol contamination.

Type	Principle	Applications
Air displacement (mechanical)	Piston + air cushion	Aqueous solutions, routine
Electronic / motorised	Motor, programmed modes	High-throughput, ergonomics
Positive displacement	Disposable piston in contact	Viscous, volatile, DNA/RNA
Dispenser	Graduated reservoir, repeated dispensing	Aliquoting, ELISA, QC

On reliability and durability: a micropipette’s performance relies on regular maintenance (cleaning, decontamination, replacement of wear parts) and on periodic recalibration, performed in-house or by a qualified provider. Following these good practices helps maintain ISO 8655 compliance, extend the instrument’s lifetime and ensure consistent results over time.

In which application areas are micropipettes used?

• Life sciences : PCR/qPCR, NGS, library preparation, Western blotting, cell culture, DNA/RNA extraction with filter tips to prevent aerosol formation.
• Microbiology : plating and inoculation, tenfold serial dilutions, antibiograms with accurate, reproducible volumes.
• Pharmaceutical/biotech : preparation of standards, HPLC/LC-MS quantification, ISO 8655 verification and calibration traceability.
• Food testing : allergen and mycotoxin analysis, high-throughput ELISAs using repeat-dispensing pipettes.
• Environment : trace contaminant measurements, analytical chemistry, volatile samples via positive displacement.
• Cosmetics/chemistry : formulation at the µL–mL scale, high viscosities handled by positive displacement or reverse pipetting.
• Quality control : aliquoting series, calibrations, documentation of systematic and random errors.

Available micropipette types

Frequently asked questions about micropipettes

How do I choose between air displacement and positive displacement?
Air displacement suits aqueous solutions. Positive displacement is best for viscous, volatile or foaming liquids because it eliminates the air cushion and reduces errors.

Is an electronic micropipette more accurate than a mechanical one?
It improves repeatability and reduces fatigue thanks to the motor and programmed profiles. Accuracy also depends on the model, the tips and the calibration.

When should I use reverse pipetting?
For foaming/viscous solutions or volumes near the minimum setting. It reduces bubbles and losses at the tip, and stabilises low-volume dispensing.

Are the parts autoclavable?
On many models, the lower module (tip cone, seal/O-ring, shaft) is autoclavable at 121 °C. Check the manual and re-lubricate the seals after sterilisation.

Do I need filter tips?
Yes for DNA/RNA, cultures, pathogens or radioactivity. The filter blocks aerosols and protects the piston and instrument, reducing cross-contamination.

How often should I calibrate?
Depending on use: routine work every 3–12 months. High criticality or extreme volumes: more often. Follow ISO 8655 and record any adjustments.

Low-retention tips: are they useful?
Yes for proteins, detergents and nucleic acids. Hydrophobic surfaces limit adhesion and improve accuracy and recovery at low volumes.

What are the essential pipetting best practices to ensure accuracy?
Select the correct volume range: ideally pipette between 35 and 100% of nominal capacity. Pre-wet the tip (2–3 cycles) to stabilise the liquid film and improve repeatability. Keep temperature consistent (pipette, tip and liquid) to minimise air-expansion errors. Hold the pipette vertical during aspiration and limit tip immersion. Pipette at a constant speed, without jerks, and pause briefly before withdrawing the tip. Change tips between samples to avoid cross-contamination.