Pipettes

A pipette is a laboratory tool commonly used in chemistry, biology, and medicine to transport a measured volume of liquid, often as a media dispenser. Pipettes come in several designs for various purposes with differing levels of accuracy and precision, from single piece glass pipettes to more complex adjustable or electronic pipettes.

Types of Pipettes

There are several types of pipettes used in the laboratory, including but not limited to:

• Volumetric pipette: Designed to measure a precise volume of liquid. It is a long, slender tube with a single graduation mark. Volumetric pipettes are known for their accuracy and are commonly used in quantitative chemistry to prepare solutions.
• Graduated pipette or Measuring pipette: Similar to the volumetric pipette, but has multiple graduation marks along its length for measuring different volumes of liquid. It offers flexibility but with slightly less accuracy.
• Micropipette: A precision instrument that can measure very small volumes of liquid, typically ranging from 0.1 µL to 1000 µL (1 mL). Micropipettes are essential in molecular biology and biochemistry for tasks requiring precise volume measurements.
• Pasteur pipette: Also known as a dropper or a teat pipette, it is a simple device used to transfer small quantities of liquid. Made of plastic or glass, it is not designed for precise measurements but is useful for general laboratory tasks.

Operation

The operation of a pipette varies depending on its type. Volumetric and graduated pipettes are often used with a Pipette bulb or pipette filler to draw and dispense liquid. Micropipettes have a plunger mechanism to aspirate and dispense liquid with high precision. Proper technique is crucial to ensure accuracy and precision when using pipettes.

Maintenance

Proper maintenance is essential for the accuracy and longevity of pipettes. This includes regular calibration, cleaning, and, when necessary, repair. Calibration ensures that the pipette dispenses the correct volume. Cleaning is important to prevent cross-contamination between samples.

Safety

When using pipettes, especially with hazardous chemicals, safety precautions should be taken. This includes wearing personal protective equipment (PPE) such as gloves and goggles, and being trained in proper pipetting techniques to avoid repetitive strain injuries.

Applications

Pipettes are used in a wide range of scientific fields for various applications, including:

• Preparing and diluting solutions in chemistry
• Transferring precise volumes of reagents in molecular biology experiments
• Measuring and dispensing drugs in pharmacies and clinical laboratories

See Also

• Laboratory equipment
• Burette
• Syringe