Pipetting and measuring liquid volumes

Pipetting is one of the most frequent operations carried out in the biochemistry laboratory. Simple Pasteur pipettes are intended for the non-quantitive transfer of liq- 

Burettes, which can be considered a special form of graduated pipette, are usually filled with a small filter funnel and liquid is dispensed via a tap. They are an essential tool in titrations for determining the concentration of compounds in solution. 

An important general rule in the quantitative handling of liquids is that the graduated vessel or pipette should be of a size appropriate to the volume being measured it is certainly not sensible to measure out a few ml of liquid in a 100 ml measuring cylinder, nor a few pi with an adjustable pipette that holds 100 pi. 

---