Patent ID: 8158259

Claim:
A multi-layered laminate comprising in ascending vertical sequence: (i) an indicator layer, (ii) an overcoat layer, (iii) a humidity control layer, (iv) a sample loading layer, and (v) a spreading layer, wherein the humidity control layer (iii) has opposing sides, the layer effective to inhibit undesirable effects of varying levels of humidity present on one side of the layer, comprising: (a) a water-insoluble, porous matrix, including a plurality of channels or through holes at least some of which extend from one side of the layer to an opposing side; and (b) one or more water-soluble, solid, polymeric substances that fill a substantial portion of the plurality of channels or through holes; and the spreading layer (v) has opposing surfaces, the layer effective to promote a desirable rate of spreading of a liquid sample applied on one surface of the layer, comprising: (a′) a water-insoluble, porous matrix, including a plurality of channels or through holes at least some of which extend from one surface to an opposing surface, the matrix further characterized as including fibers having an average length falling in the range of about 50 μm to about 400 μm; (b′) one or more water-soluble, solid, polymeric substances that fill a substantial portion of the plurality of channels or through holes; and (c′) one or more hydrophilic, super absorbent materials.