A bacteriological pipette, sometimes called a bacterial pipette or bacterial pipet, is a type of serological pipette used for diary inspection and tissue culturing. Most bacteriological pipettes have bi-directional graduations for measuring the amount of liquid in the chamber and the amount of liquid dispensed. Polystyrene bacteriological pipettes that have a 1.1mL or 2.2mL volume are designed for inspecting dairy products. Dispensers are used to extract the sample from the container and dispense it to the receiving receptacle. Filter plugs on some models prevent the sample from contaminating the dispenser. Features to consider when selecting a bacteriological pipet include volume capacity, material construction, purpose or use, and standards met.