Frazil ice conjugate assay device and method

摘要

An improved apparatus and method for dispersion of a labeling conjugate in a diagnostic assay, the result being a one-step assay. By eliminating a conjugate pad as in conventional lateral diagnostic devices, and forming a frazil ice pellicle (FIP), rehydration and flow are improved resulting in better reproducibility, improved sensitivity, and reduced costs of individual assay devices. The formation of a frazil ice film formed on a super cooled surface of a sample receiving means simplifies assay assembly. Lyophilization of the FIP improves the release of a sample/analyte/label matrix into a macro channel as in a direct flow assay, while at the same time allowing reagents to mix and flow, thereby optimizing the assay performance. The reagents of the conjugate and the formation of the FIP stabilize the conjugate proteins and provide extended shelf life to the diagnostic assay device.

主权项

1. A test strip for an assay device, the test strip comprising:
an elongated porous membrane having a top surface and a bottom surface, having a proximal end and a distal end, and having at least one test line; a sample pad adjacent the proximal end of said porous membrane, said sample pad having a first surface and a second surface, said first surface being parallel with and oriented in the same direction as said bottom surface of said porous membrane, said sample pad being impregnated to a condition of approximate saturation with a selective mix of at least two of water, buffers, protectants, proteins, or surfactants and then being frozen at about −80° C. or below; a conjugate pellicle on said first surface of said previously frozen sample pad, said sample pad and said conjugate pellicle having been lyophilized; and means for providing fluid communication between said conjugate pellicle and said porous membrane.