Pipette having integrated filtration assembly

The present invention is a pipette-filtration assembly having a main body defining a first channel, a second channel, a first valve, and a second valve. The first valve is associated with the first channel and permits flow in a first direction while substantially hindering flow in a second direction. The second valve is associated with the second channel and permits flow in the second direction while substantially hindering flow in the first direction. At least one filter is used to filter a fluid sample as the fluid sample flows in the first direction and/or the second direction. The pipette-filtration assembly is preferably disposable and includes one or two stages of integral filtration, primarily for use with an air-displacement pipetting or transfer system.