Pipetters

Pipetters, or pipettors, are devices used to transfer precise volumes of liquid in laboratory settings. They typically consist of a handle with a plunger and a volume control, and they utilize disposable tips to prevent cross-contamination. Pipetters range from manual to electronic variants and are essential for accurate liquid handling in experiments and diagnostics.

Types of pipetters include micropipettes with adjustable volumes (commonly from about 0.1 µL to 1000 µL), which can be air-displacement or positive-displacement models. Multichannel pipettes allow simultaneous handling of multiple wells, while fixed-volume pipettes dispense a single, specified volume. Electronic pipettes automate aspiration and dispensing sequences and can improve repeatability and ergonomics.

Operation and technique emphasize accuracy and contamination control. Typical steps involve attaching a sterile tip, pre-wetting the tip, setting the desired volume, and using a two-stop plunger: the first stop to aspirate and the second stop to dispense. Proper technique includes keeping the tip vertical, avoiding air bubbles, and dispensing slowly to minimize splashing. Regular calibration and tip compatibility checks are important for maintaining performance.

Calibration and standards: International guidelines, such as ISO 8655, govern the calibration, testing, and maintenance of pipettes. Labs perform routine performance verification, adjust for temperature and liquid density, and document traceability to ensure measurement accuracy.

Applications: Pipetters are used across biology, chemistry, clinical laboratories, and industry for tasks such as reagent dispensing, serial dilutions, sample preparation, and plate-based assays, including genomics, proteomics, and drug screening.

Ergonomics and safety: Prolonged pipetting can contribute to musculoskeletal strain, so proper grip, posture, and break schedules are recommended. Practices to prevent contamination include frequent tip changes and maintenance of clean workspaces.