Abstract: The present invention provides a membrane comprising (a) polymer solids comprising 60 wt. % or more of a fully synthetic organic polymer and optionally about 40 wt. % or less of a polymer of natural origin and (b) a cellulose compound which allows for the detection of a biological molecule of interest, wherein the cellulose compound is uniformly distributed throughout the surface of the membrane. The present invention also provides methods of preparing and using such membranes.

Abstract: In accordance with the invention there is provided a water filter and water filter cartridge having an upper water filtering layer containing charcoal particles, a lower filtering layer having a submicron pore size and an intermediate filtering layer having a pore size greater than that of the lower layer but less than the particle size of the charcoal in the upper layer.

Abstract: In accordance with the invention there is provided a water filtering device for attachment to a faucet comprising a generally tubular passage with an inlet for water from the faucet at its upper end and an outlet for water at the lower end, an annular water filtering chamber surrounding the passage, openings between the lower axial end of said chamber and the lower portion of said passage, openings between the upper axial end of said chamber and the upper portion of said passage, and a valve in said passage movable for blocking the flow of water directly from the upper portion of said passage to the lower portion of said passage whereby when said valve is closed water from the faucet is caused to flow from said passage into and through said filtering chamber and then back into said passage and out of the water outlet.