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Pipette Basics: A Complete Guide to Types, Technique and Calibration
What is a Pipette?
A pipette is a precision instrument designed to accurately measure and transfer small volumes of liquid. Whether you’re pipetting enzymes, reagents, or cell cultures, understanding pipettes is fundamental to achieving reliable and reproducible results in your lab.
Types of Pipettes
Pipettes come in a range of designs, each suited to specific volumes, liquids, and laboratory applications. Understanding the differences between pipette types helps you select the right tool for your workflow and ensures your results are accurate and reproducible.
Mason Technology partners with leading pipette suppliers Eppendorf and Labnet to offer a comprehensive range of manual and electronic pipettes for every laboratory need.
| Pipette Type | Volume Range | Best Use Case | Accuracy Level |
|---|---|---|---|
| Volumetric Pipette | Fixed (1mL – 200mL) | Preparing standard solutions, titrations | Very High |
| Graduated (Mohr) Pipette | Variable (0.1mL – 25mL) | General transfers, serial dilutions, titrations | Moderate |
| Micropipette (Air Displacement) | 0.1µL – 1000µL | PCR, ELISA, molecular biology, serial dilutions | Very High |
| Pasteur / Transfer Pipette | Drops to ~3mL | Rough transfers, blood sampling, non-critical work | Low |
| Serological Pipette | 1mL – 50mL | Cell culture, media preparation, reagent mixing | Moderate–High |
| Electronic Pipette | 0.5µL – 50mL | High-throughput workflows, repetitive dispensing | Very High |
| Positive Displacement Pipette | 1µL – 10mL | Viscous or volatile liquids, contamination-sensitive work | Very High |
Volumetric Pipettes
Volumetric Pipettes have a single graduation mark near the top. They deliver a fixed volume of liquid.
Use Cases:
- Precise measurement of a specific volume (e.g., 10 mL or 25 mL).
- Commonly used for preparing standard solutions.
Application Examples:
- Creation of serial dilutions and stock solutions.
- Titrations and volumetric analysis.
How do Volumetric Pipettes work?
They offer highly accurate volume measurement. They have a large bulb with a long, narrow portion calibrated for a specific volume (e.g., 10, 25, or 50 mL).
Process:
To use, draw up the liquid to the calibration mark, then release it into the receiving vessel. These are commonly used in analytical chemistry for preparing laboratory solutions and titrations.
Graduated Pipettes (Mohr)
Graduated Pipettes have multiple graduation marks along their length. You can adjust the volume by choosing the appropriate mark.
Use Cases:
- Delivering variable volumes within a specified range.
- Useful for titrations and serial dilutions.
Application Examples:
- Adding culture media to cells.
How do Graduated Pipettes (Mohr) work?
They have straight-walled tubes with uniform graduation marks along their length. They are less accurate than volumetric but still useful for various applications.
Process:
They are commonly used in titrations and clinical analyses. They allow bidirectional measurement and controlled liquid flow.
Pasteur Pipettes (Transfer)
Pasteur Pipettes are simple glass or plastic tubes with a tapered end.
Use Cases:
- Transferring small volumes (usually drops) without precise measurement.
- Ideal for transferring liquids between containers.
Application Examples:
- Blood sampling:They are used to precisely collect blood samples for diagnostic tests, monitoring a patient’s condition or conducting blood transfusions.
How do Pasteur Pipettes (Transfer) work?
They are disposable plastic devices that transfer small quantities of liquid without cross-contamination.
Process:
These are commonly used for rough measurements in urinalysis, hematology, immunology, and blood banking.
Serological Pipettes
Graduated Pipette with a wide bore and a bulb at the top.
Use Cases:
- Dispensing larger volumes (e.g., 5 mL, 10 mL or 25 mL).
- Commonly used in cell culture and media preparation.
Application Examples:
- Adding culture media to cells.
How do Serological Pipettes work?
They transfer liquids measured in milliliters (mL) using an air displacement method. They are calibrated to the tip and commonly used in cell culture, urinalysis, and blood banking.
Process:
Dispense and aspirate liquids accurately. They can mix reagents, cell suspensions, and chemical solutions.
Positive Displacement Pipettes
- Direct Contact: In positive displacement pipettes, the liquid directly contacts the piston. These pipettes are either dispensers (for single aliquots) or repeaters (for multiple aliquots of the same size).
- Dispenser Tips: Tips for positive displacement pipettes are often called dispenser tips.
Use Cases:
- Volatile Liquids: Positive displacement pipettes are ideal for pipetting volatile solutions that might escape air-displacement tips.
- Viscous Solutions: They handle both aqueous and non-aqueous viscous solutions effectively.
- Highly Accurate: Positive displacement pipettes provide precise volumes, especially when dealing with challenging samples.
- Single-Use Applications: They’re suitable for applications where contamination risk must be minimized.
Application Examples:
- Pipetting viscous or volatile liquids
How do Positive Displacement Pipettes work?
They use disposable tips that directly displace the liquid. Ideal for viscous or volatile samples.
Process:
Aspirate the liquid using a disposable tip. These are suitable for challenging samples.
Electronic Pipettes
- Fully Electronic: This type has motorized components for aspiration and dispensing. They feature an intuitive interface with a digital display for volume selection.
- Battery-Powered: They are portable and don’t require a separate power source during use.
- Memory Function: Some models allow you to save pipetting protocols, making repetitive tasks more efficient.
Use Cases:
- Repetitive Pipetting: They excel in high-throughput workflows, such as ELISA assays, PCR setup, and plate filling.
- Volatile Solutions: Unlike air-displacement, these can handle volatile liquids without leakage.
- Viscous Solutions: They work well with both aqueous and non-aqueous viscous solutions(e.g., glycerol, buffers) due to their consistent performance.
- Ease of Calibration: Electronic pipettes simplify calibration and ensure accurate results.
Application Examples:
- Serial Dilutions
- ELISA plate preparation
How do Electronic Pipettes work?
They use a battery-powered motor to replace manual piston movement, improving ergonomics and reducing force.
Process:
Press the main button to aspirate and dispense. They are ideal for repetitive pipetting tasks.
Micropipettes (Air Displacement Pipettes)
Micropipettes are precision instruments for microliter (µL) volumes.
Piston-Driven Mechanism: They contains a piston that moves up and down within the shaft
No Direct Contact: The liquid remains separated from the piston by an air cushion, preventing direct contact.
Subtypes:
Single-Channel:
- Dispense a single volume at a time.
- Commonly used in molecular biology and biochemistry.
Multi-Channel:
- Simultaneously dispense multiple samples (e.g., 8 or 12 channels).
- Efficient for high-throughput work.
Use Cases:
- Routine Lab Work: Dispensing small amounts of aqueous or non-viscous liquids.
- Contamination-Sensitive Applications: Ensuring contamination-free liquid handling.
- Cost-Effective Solutions: When specialized capillary piston tips aren’t necessary
Application Examples:
- Serial Dilutions
- ELISA plate preparation
How do Micropipettes work?
They are adjustable volume, and used for precise measurements in microliters (µL). They rely on air displacement or positive displacement methods.
Process:
Set the desired volume, aspirate the liquid, and dispense it accurately. These are essential in molecular biology, PCR, and other sensitive assays.
Pipette Calibration and Maintenance
Pipettes are precision instruments, but like all mechanical devices, they drift over time. Regular use, accidental drops, chemical exposure, and temperature fluctuations all affect internal components – meaning the volume a pipette delivers can gradually deviate from the volume it displays. In a research or production environment, this matters enormously.
In pharmaceutical manufacturing, food production, and clinical diagnostics, volume inaccuracy can compromise product quality, invalidate assay results, and create serious compliance risk. For laboratories operating under GMP, ISO, or regulatory frameworks such as the Irish Medicines Board or FDA guidelines, calibrated and documented pipette performance is not optional – it is a regulatory requirement.
Uncalibrated pipettes are one of the most common and easily preventable sources of systematic error in laboratory workflows.
Frequently Asked Questions
How often should pipettes be calibrated?
ISO 8655 recommends calibrating pipettes at regular intervals based on frequency of use and application risk. For most laboratory environments, every 3 – 6 months is appropriate for high-use or GMP-critical pipettes, and every 6 – 12 months for lower-risk applications. Pipettes should also be calibrated immediately after any drop or physical incident, regardless of the scheduled interval.
What is the difference between a volumetric and a graduated pipette?
A volumetric pipette is designed to deliver one fixed, highly accurate volume – for example, exactly 10mL or 25mL. It has a single calibration mark and is used where precision is critical, such as preparing standard solutions. A graduated (Mohr) pipette has multiple graduation marks along its length, allowing variable volumes to be delivered within a range. It is less precise than a volumetric pipette but more flexible for general use.
What is a micropipette used for?
Micropipettes are used to measure and transfer very small volumes of liquid, typically in the range of 0.1µL to 1000µL. They are the workhorse of molecular biology, biochemistry, and clinical diagnostics – used in applications such as PCR setup, ELISA, serial dilutions, DNA/RNA quantification, and cell-based assays. Most micropipettes use an air displacement mechanism and are available in single-channel and multichannel formats.
How accurate are electronic pipettes?
Electronic pipettes offer comparable or superior accuracy to manual pipettes, with the added benefit of eliminating operator-dependent variability. Because aspiration and dispensing are motor-controlled, results are more consistent across repeated actions – particularly during high-throughput workflows. Leading models such as the Eppendorf Xplorer and Labnet Excel offer accuracy within ±1–3% depending on volume and liquid type, with built-in features for mixing, dilution series, and multiple dispensing modes.
What is positive displacement pipetting?
Positive displacement pipetting uses a disposable piston-tip assembly where the piston makes direct contact with the liquid – there is no air cushion between the piston and the sample. This makes positive displacement pipettes ideal for viscous liquids such as glycerol, volatile solvents that would evaporate from an air gap, and applications where cross-contamination between samples must be eliminated. The Eppendorf Multipette E3 with Combitips advanced is a leading example of this technology.
Can pipettes be repaired or should they be replaced?
In many cases, pipettes can be repaired and recalibrated rather than replaced – making maintenance a more cost-effective option, particularly for high-quality instruments. Common issues such as worn seals, damaged O-rings, or a stiff plunger are typically repairable by a qualified service technician. However, if a pipette has suffered significant physical damage, shows persistent calibration failure after adjustment, or is no longer supported by the manufacturer, replacement is usually the better choice. If you are unsure, our team can assess your pipettes and advise on repair versus replacement.
Need Pipettes or Pipette Calibration Services?
Mason Technology stocks a full range of Eppendorf and Labnet pipettes and provides INAB-accredited pipette calibration services across Ireland. Whether you need a new pipette, replacement tips, or a calibration certificate for your next audit, our team is here to help.
