A new material and a new device useful in solid phase assays fijacionen to determine the presence or amount of an analyte in a test sample

A NEW MATERIAL AND A NEW DEVICE USEFUL binding assays Solid Phase TO DETERMINE presence or amount of an analyte in a test sample, INCLUDING antigens or antibodies. The material comprises a porous matrix of fibers and a plurality of solid particles, substantially spherical, having a diameter APPROXIMATE AVERAGE 0.1 to 5 microns. The particles are retained and immobilized on the fibers of the matrix. Preferably, the particles have on their surface a ABLE TO REACT WITH SUBSTANCE analyte in the sample and the diameter average particle is less than the plot or PORE THROUGH THE MATRIX. DEVICE, in a preferred embodiment, comprises a layer SUBSTANTIALLY FLAT MATERIAL DESCRIBED.