Patent ID: 8906645

Claim:
A microbial detection article comprising: a base member comprising a self-supporting water impervious substrate with a first major surface and a second major surface that is generally opposed to the first major surface; a filter assembly defining a filter assembly aperture therein, and having a composite filter body mounted across the filter assembly aperture; wherein the composite filter body comprises: 1) a filter support layer having the filter assembly aperture, 2) a microporous membrane positioned on a first side of the filter support, wherein the microporous membrane overlays the filter assembly aperture and extends beyond the perimeter of the filter assembly aperture, and 3) a water-absorbent layer positioned on a second side of the filter support opposite the microporous membrane, wherein the water absorbent layer is positioned under the filter assembly aperture, is in fluid communication with the microporous membrane, and extends beyond the perimeter of the filter assembly aperture, wherein the water absorbent layer comprises a fibrous substrate functionalized with a grafted hydrogel polymer; and a cover sheet; wherein the filter assembly is positioned between the cover sheet and the base member; the filter assembly is coupled to the cover sheet, to the base member, or to both; and the water-absorbent layer is positioned between the microporous membrane and the base member.