Classification of micropipettes and uses

What is a micropipette?

A micropipette is an indispensable tool in modern science, especially in the fields of molecular biology, cellular biology, medicine, and chemical analysis. They allow for precise transport of small liquid volumes, typically measured in microliters, ranging from 0.1 µL to 1000 µL. With micropipettes, experiments can be conducted with high accuracy and reproducibility.

Classification of micropipettes

Micropipettes can be classified in various ways, with the most common being based on volume, number of channels, operating principle, and mechanism of action. To be more concise and familiar with the Vietnamese term, GeneSmart will use the term “pipette” to refer to the term “micropipette”.

Classification by volume

Fixed volume pipettes: Only one volume option is available, usually suitable for optimized processes with no variations. This type of pipette has the advantages of being cost-effective, highly accurate, and more durable than adjustable volume pipettes.

Adjustable volume pipettes: Allow for the adjustment of volume within its pipetting range. This type of pipette is favored in many laboratories for its flexibility, catering to diverse user needs.

Classification by number of channels

Single-channel pipettes: Allow users to transfer a single aliquot at a time. This type of pipette is extremely suitable for low-throughput experimental work, where each treatment requires a different volume.

Multi-channel pipettes: Common setups are 8-/12-channels but 4-, 6-, 16-, 48- or 96-channel sets are also available. This type of pipette can quickly fill a 96-/384-/1536-well microplate, which may contain samples for applications such as DNA amplification, ELISA (diagnostic test), kinetic studies and molecular screening.

Classification by operating principle

Air displacement pipettes: Have an air cushion between the piston and the sample. Before aspirating the liquid, the piston descends, pushing out a volume of air corresponding to the required volume of liquid. Laboratories typically use air displacement pipettes, as they’re less expensive and well suited to most liquids, including viscous and volatile liquids – as long as the correct technique and pipette tips are used.

Positive displacement pipettes: The aspiration process is similar to air displacement pipettes, but the piston is in direct contact with the sample. To avoid cross-contamination, the piston is a part of disposable tip, which makes the consumable cost become relatively high. This type of pipette is suitable for aspirating liquids that are highly volatile or viscous. They are also more accurate when pipetting hot or cold samples, as they are not affected by temperature variations.

Classification by operating mechanism

Mechanical pipettes: Also known as manual pipettes, they are widely used due to their user-friendliness and low cost. Some mechanical pipettes have multi-dispense function (manual repeater pipette).

Electronic pipettes: The biggest barrier to the widespread use of electronic pipettes in laboratories is the costly equipment. However, if the budget allows, the following benefits may make you reconsider:

• Health protection: Minimize the risk of repetitive strain injuries from pipetting and adjusting volume.
• Higher accuracy: Reduce manual errors and prevent operator-to-operator variability..
• Time-saving: Users do not need a break between pipetting, and most electronic pipettes also have multi-dispense function.