There are several types of single-channel pipettes used in the lab:
– Manual pipettes – Require the user to manually aspirate and dispense the liquid using an analog or digital voltmeter and a lever or plunger. Good for general use.
– Electronic pipettes – Use an electric motor to control aspiration, dispensing, and tip ejection. Allow precise volume setting and can time dispensing. More expensive but very precise.
– Adjustable-volume pipettes – Allow the volume setting to be changed for aspiration/dispensing different amounts with the same pipette. Flexible option.
– Fixed-volume pipettes – Designed to only pipette one pre-set volume. Inexpensive but less flexible. Good for repetitive pipetting of the same volume.
– Piston-stroke pipettes – Volumes adjusted by how far the piston/plunger is depressed. No volumeter. Basic and inexpensive but less accurate.
– Positive-displacement pipettes – Very precise by always displacing the same volume. Popular for molecular biology applications.
– Standard pipettes – For general volumes from 1 microliter to 1 milliliter. The most common single-channel type.
– Micropipettes – Designed for microliter volumes, good for very small volumes and dilutions.
– Repeating pipettes – Allows dispensing multiple aliquots of the same volume with one aspiration. Convenient for plates.
The needs of the application and desired accuracy dictate what type of single-channel pipette is most appropriate to select. Training on proper technique is essential.
