Filtration device and method

Embodiments of the present invention relate to a filtration device and method for filtering liquids. In conventional devices, a liquid is placed in a vial, and a plunger, having a filter membrane located at one end, is depressed into the vial, causing the liquid to pass through the filter membrane into the interior of the plunger, where it is stored until required for further processing. However, such plungers are typically made of a plastics material. It is undesirable to store the filtered liquid in contact with plastics for extended periods of time, as contaminants may leach from the plastics material into the sample. In embodiments of the present invention, a filtrate receptacle made from a different material to the plunger, such as a glass material, is located in the interior of the plunger and the filtered liquid collected in the filtrate receptacle after passing through the filter membrane. This allows the filtered liquid to be held isolated from the plastics material, thereby protecting it from contamination.