Abstract: A method and apparatus for separation and filtration of particulate matter of sediment from a liquid sample. The system includes a unitary filter assembly having an intermediate fibrous filter material disposed between two layers of porous, relatively rigid plastic material. The unitary filter assembly is pressed axially toward the closed end of a sample container, such as a test tube, resulting in an upward flow of filtrate with compaction and retention of the particulates between the unitary filter assembly and the closed end of the sample container. The filter assembly is free of orientation criticality and may be readily adapted to automated handling in multiple tests or assays.