Filtration apparatus

Filtration apparatus comprises first and second housing portions 10 and 12 which are hinged together at 14, a relatively coarse filter (32) being releasably retained on shoulder 20 of the first housing portion and a fine filter being releasably mounted between the 9 housing portions. In use suction is applied to outlet 24 to draw suspension through the filters, coarse filter (32) removing solid particles but allowing bacteria to pass through to be collected on the fine filter for subsequent processing and examination. The coarse filter is wire mesh of 4 to 15 micron pore size, the fine filter in a hydrophilic membrane of 0.1 to 1.0 microns. The apparatus is used in testing food, drugs and body fluids, the coarse filter removing particles which would interfere with the examination of the fine filter.