MILLIPORE FILTER

A thin membrane of modified cellulose that is used as a filter in the bacteriological examination of water or wastewater. The filter is typically used to filter a given quantity of aqueous sample followed by transfer of the filter to the surface of a special medium to allow for the growth of the bacteria that have been retained by the filter. At one time the only commercial source of these filters was the Millipore Corporation, although presently a variety of sources are now available. Even so, the common name Millipore filter has been retained.