Membrane-containing wells for microtitration and microfiltration

Claim 1

A well for use in performing microtitration or microfiltration, said well comprising a hollow tubular wall having an axis, upper and lower axially spaced ends, an inner surface, and a lip extending radially inwardly of said inner surface at said lower end, said lip having a distal surface defining an aperture; a membrane having a top surface, a bottom surface, and a periphery, and having a shape and size adapted so that a peripheral portion of said membrane adjacent said periphery contacts the upper surface of said lip, with a central portion of said membrane extending across said aperture; a generally annular ring having an axis, an outer surface, and a lower surface having a width dimension radially of said ring that is generally the same as the radial width of the top surface of said lip, said ring being retained in a predetermined position along the inner surface of said wall with the lower surface of said ring against the upper surface of said membrane and pressing said peripheral portion of the membrane against the lip, and means for retaining said outer surface of said ring in engagement with the inner surface of said wall to retain said ring in said predetermined position along said wall.