How is pipetting performed?

Different types of glass pipettes

There are two main types of glass pipettes:

Volumetric pipettes can have 1 graduation mark or 2 graduation marks
Graduated pipettes have graduations which vary according to the volume

Volumetric pipette with 2 calibration lines

Illustration of a 2-line volumetric pipette

Volumetric pipette with 1 calibration line

Illustration of a volumetric pipette with 1 line

Graduated pipette

Illustration of a graduated pipette

Glass pipettes are also divided into two precision classes usually indicated on the pipette: class A and class B.

Table showing the precision of pipettes according to the class and the volume

Class A pipettes are more accurate than Class B pipettes. However, this precision is given for a temperature of 20°C, and any deviation from this reference leads to a decrease in precision.