Pasteur Pipettes – A History
Famous 19th Century scientist, Louis Pasteur, is well remembered as a founder of medical microbiology. After three of his children died of typhoid before reaching adulthood, Pasteur focused on trying to understand the cause and prevention of diseases.
He is best known for inventing a method to stop milk and wine from causing sickness, the process known as pasteurization.
At the time people thought that spontaneous generation was responsible for the spoiling of food or beverages. However, Pasteur demonstrated that fermentation is caused by the growth of micro-organisms contaminating the materials from outside, as spores on dust. This became known as Germ Theory.
Once this understanding was clearly established, the need to keep everything clean and germ free became fundamental to all experiments. To achieve this Pasteur invented the pipette to ensure that liquids could be removed from or transferred between vessels without introducing foreign elements that could contaminate the contents. This valuable tool became known as the ‘Pasteur pipette’, a term still widely used today.
Pasteur used long thin glass tubes cut into appropriate lengths. The ends were plugged with cotton wool to prevent any contaminants from entering. The centre of the tube was then heated until molten and quickly pulled apart to make a long and very thin tube between the larger ends. The tube was then snapped in half to create two fine tipped pipettes.
Such pipettes have been used in laboratories ever since and may also be referred to as transfer pipettes, bulb pipettes, dropper pipettes or teat pipettes. Perfect for selecting small samples of microorganisms to transfer to a new growth medium, they helped Pasteur to isolate pure cultures. The addition of a rubber teat made aspiration and dispensing of the sample, simple and very quick.