P B Diagnostic Systems, Inc.

Gerd Grenner

Ernest W Long

Shai Inbar

There is described an assay element suitable for use in an automated analytical test instrument for assaying a fluid sample. The element includes a thin porous member possessing a high degree of capillarity such as a fibrous mesh pad supported within a guide defined by surfaces contiguous the porous member. The dimensions of the porous member and its degree of capillarity are such as to provide for capillary transport of fluid through the member. A fluid dispenser and a fluid collecting chamber are disposed contiguous to opposed ends of the porous member. The fluid dispenser is formed as a well with a port at the bottom of the well, the port being contiguous the porous member and having a ridge extending along a perimeter of the port. The ridge protrudes into the porous member a distance sufficient for entraining fluid present in the well to propagate within the member rather than along an interface between a surface of the member and guide surfaces which hold it in place. Reservoirs may also be provided in the housing for storing reagents, mixing fluids and diluting samples so as to provide a self contained assay element. Optionally, and preferably, there may be an opening in the housing to provide fluid access directly to the central area of the porous member.

Assay element

A liquid transport system provides controlled flow of liquid in a liquid flow zone between two surfaces wherein one surface includes a plurality of projections, or raised areas, arranged substantially throughout the surface in the liquid flow zone and an aperture for allowing the introduction of liquid between the two surfaces. In a preferred embodiment the projections on the first surface are arranged in parallel spaced rows and parallel spaced columns. The second surface may be one surface of a layer of a diagnostic assay element.

Liquid transport system

An element for analysis of a liquid sample including a capillary containing a fixed reagent in fluid communication with reagent reservoirs and a waste liquid reservoir. A sample introducing means is provided which permits analyte in a sample to interact with the fixed reagent. A labelled reagent is provided which interacts with either the fixed reagent or the analyte in a manner which permits detection of the concentration of analyte in the sample. The capillary, reagent reservoirs, waste liquid reservoir and the sample introducing means are arranged within a common housing so that reagent waste liquid need not be removed from the element.

Self contained immunoassay element

A biological diagnostic device and process for efficiently and accurately analyzing a sample of a biological fluid for in analyte of interest. The device, which is a preferred embodiment utilized for the analysis of whole blood samples, comprises a diagnostic test element and a sample application unit comprising a fluid delivery element and means for providing sample fluid to the fluid delivery element. The fluid delivery element comprises a layer having a plurality of grooves, or channels, in the surface thereof which is adjacent the test element. The fluid which is provided to the grooves is subsequently delivered to the test element.

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Lincoln, MA, United States of America

Gerd Grenner