Devices and methods for a multi-level, semi-quantitative immunodiffusion assay

A device for determining the presence of an analyte, comprising:

• a layer including a continuous porous medium deposited thereon;
• a fluid pathway defined by fluid barriers in the porous medium, at least a portion of the barriers defining a capillary channel;
• and
• an analysis zone within the fluid pathway comprising a plurality of binding zones for binding and immobilizing the analyte, each binding zone being defined by a concentration of a binding reagent immobilized on the medium, wherein the fluid barriers are screen-printed barriers.

A device for determining the presence of an analyte, comprising:

• a layer including a continuous porous medium deposited thereon;
• a fluid pathway defined by fluid barriers in the porous medium, at least a portion of the barriers defining a capillary channel;
• and
• an analysis zone within the fluid pathway comprising a plurality of binding zones for binding and immobilizing the analyte, each binding zone being defined by a concentration of a binding reagent immobilized on the medium, wherein the fluid barriers are etched barriers.

A device for determining the presence of an analyte, comprising:

• a layer including a continuous porous medium deposited thereon;
• a fluid pathway defined by fluid barriers in the porous medium, at least a portion of the barriers defining a capillary channel;
• and
• an analysis zone within the fluid pathway comprising a plurality of binding zones for binding and immobilizing the analyte, each binding zone being defined by a concentration of a binding reagent immobilized on the medium, wherein the fluid barriers are serrated barriers.

A device for determining the presence of an analyte, comprising:

• a layer including a continuous porous medium deposited thereon;
• a fluid pathway defined by fluid barriers in the porous medium, at least a portion of the barriers defining a capillary channel;
• and
• an analysis zone within the fluid pathway comprising a plurality of binding zones for binding and immobilizing the analyte, each binding zone being defined by a concentration of a binding reagent immobilized on the medium, wherein the fluid barriers are defined by edges of the layer.

A device for determining the presence of an analyte, comprising:

• a layer including a continuous porous medium deposited thereon;
• a fluid pathway defined by fluid barriers in the porous medium, at least a portion of the barriers defining a capillary channel;
• an analysis zone within the fluid pathway comprising a plurality of binding zones for binding and immobilizing the analyte, each binding zone being defined by a concentration of a binding reagent immobilized on the medium;
• and
• a reservoir zone at a second end of the fluid pathway and upstream of the analysis zone, to facilitate removal of fluid from the analysis zone, wherein the reservoir zone comprises a series of capillary channels in parallel arrangement with each other, each capillary channel being contiguous with the fluid pathway.

A device for determining the presence of an analyte, comprising:

• a layer including a continuous porous medium deposited thereon;
• a fluid pathway defined by fluid barriers in the porous medium, at least a portion of the barriers defining a capillary channel;
• and
• an analysis zone within the fluid pathway comprising a plurality of binding zones for binding and immobilizing the analyte, each binding zone being defined by a concentration of a binding reagent immobilized on the medium,
• wherein the plurality of binding zones is arranged substantially linearly and sequentially with respect to a direction of fluid flow, and a concentration of binding agent in the binding zones decreases successively in the direction of fluid flow.

A device for determining the presence of an analyte, comprising:

• a layer including a continuous porous medium deposited thereon;
• a fluid pathway defined by fluid barriers in the porous medium, at least a portion of the barriers defining a capillary channel;
• and
• an analysis zone within the fluid pathway comprising a plurality of binding zones for binding and immobilizing the analyte, each binding zone being defined by a concentration of a binding reagent immobilized on the medium, wherein the concentration of binding reagent immobilized on the medium defines a maximum threshold detection level.