Diagnostic device for analyte detection
View Patent ↗The present invention provides a hand-held device of the type useful to perform an in vitro immunodiagnostic assay for an analyte of interest. In embodiments of the invention, the device incorporates a carrier for conducting the assay which comprises an array of pads including a sample pad, a narrow detection pad for detecting analyte, and a bridging pad coupled in flow communication therebetween. The device is provided with a housing adapted to deliver sample onto the carrier as a linear band having a width greater than the detection pad. In combination, these features yield a device that retains the sensitivity required for diagnostic accuracy, yet is improved in terms of cost and ease of manufacture.
1. A device of the type useful to perform a lateral flow immunodiagnostic assay for one or more target analytes, the device comprising:
(a) a carrier for conducting the flow of sample along a path, the carrier comprising:
a sample receiving zone comprising a detectably labeled, mobile detector reagent for binding to the target analyte, and
an analyte detection zone downstream of the sample receiving zone and comprising an immobilized capture reagent for capturing a complex formed by said analyte and said detector reagent, and
(b) a housing for receiving the carrier, the housing comprising
a sample receiving system and
a sample deposition system in flow communication with the sample receiving system and the carrier, wherein the sample deposition system delivers sample from the sample receiving system onto the carrier as a sample band that is essentially linear and has a width greater than the width of the analyte detection zone, the width being transverse to the path of sample flow.
2. The device according to claim 1 , wherein the sample receiving zone and the analyte detection zone are defined on distinct carrier pads having an upper surface and a lower surface, and wherein said pads are coupled for sample flow by a bridging pad.
3. The device according to claim 2 , wherein the bridging pad and the analyte detection zone pad are held in flow communication with one another through a wettable barrier layer that contacts both the bridging pad and the analyte detection zone pad.
4. The device according to claim 3 , wherein the bridging pad has a width narrower than the length of the sample band deposited from the sample deposition system.
5. The device according to claim 3 , wherein the sample deposition system comprises
a sample inlet system and
a sample deposition channel in communication with the sample inlet system to deliver sample to a sample deposition site on the carrier.
6. The device according to claim 5 , wherein the sample deposition channel is integrated within the housing.
7. The device according to claim 1 , wherein the detectably labeled, mobile detector reagent is labeled with a tag selected from gold sol, enzyme, fluorophore, or lumiphore.
8. The device according to claim 1 , wherein the analyte detection zone further comprises an immobilized binding partner that is specific for the detector reagent and non-specific for the analyte.
9. The device according to claim 2 , wherein the bridging pad has a lower surface in contact with at least a portion of the sample receiving zone pad and at least a portion of the analyte detection zone pad.
10. The device according to claim 2 , wherein the sample receiving zone pad comprises a porous material.
11. The device according to claim 2 , wherein the analyte detection zone pad comprises a porous material.
12. The device according to claim 2 , wherein the bridging pad comprises a porous material.
13. The device according to claim 3 , wherein the wettable barrier layer is water-impermeable and comprises a translucent or transparent material.
14. The device according to claim 5 , wherein the sample inlet system comprises:
a sample reservoir in communication with the sample deposition channel; and
a conduit in communication with the sample inlet system and the sample reservoir to conduct sample flow.
15. The device according to claim 14 , wherein the conduit is reticulated.
16. The device according to claim 5 , wherein the length of the sample deposition channel is greater than the width of the analyte detection zone.