pipet

Pipet, or pipette in its more common form, is a laboratory instrument used to transfer precise volumes of liquid. The term pipet is an alternate spelling or a verb form meaning to transfer liquid with a pipette. Pipets are essential in chemistry, biology, medicine, and environmental analysis for tasks ranging from basic liquid handling to highly quantitative measurements.

Pipets come in several styles, with micropipettes being the most widespread for small volumes, and volumetric or measuring pipettes used for larger volumes. Modern pipets are typically adjustable and may be air-displacement or positive-displacement devices. They usually operate with disposable tips to prevent cross-contamination; the tip is attached, the volume is set, the device is primed, and liquid is aspirated and dispensed with care. Proper technique, including avoiding bubbles and maintaining a vertical stance during aspiration, directly affects accuracy.

Calibration and quality control are important for reliable results. Pipets are manufactured to specified accuracy and precision, and they require periodic calibration and servicing according to standards such as ISO 8655. Routine maintenance includes cleaning, proper storage, and tip management. Incorrect handling, poor tip fit, or miscalibrated settings can introduce systematic or random errors.

Safety and contamination control are also central. Use clean tips, change tips between samples as needed, and dispose of used tips according to laboratory protocol. While pipet can refer to the instrument or the act of pipetting, the term generally denotes a family of devices designed for precise liquid transfer in a wide range of laboratory applications.