US4920046A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process, test device, and test kit for a rapid assay having a visible readout
Assignee: Becton Dickinson and Co
•
Filing: 1987-10-08
•
Granted: 1990-04-24
•
Expires: 2007-10-08
Abstract
Abstract A flow through test device and assay kit suitable for use by unskilled technicians is described. The flow through device has a porous support and an absorptive layer. The device is constructed for control of flow rates so that a tracer having a visible particulate label can be used. Optional flow control and porous spacer layers may be included.
Inventors
- 👤 Edward McFarland
- 👤 Keith Uithoven
- 👤 Jeffrey Carlson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:53
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/569; G01N33/56911; G01N33/543; G01N33/54366; G01N33/56961; G01N33/58; G01N33/585; G01N33/586; Y; Y10; Y10S; Y10S435/00; Y10S435/81; Y10S435/975; Y10S436/00; Y10S436/80; Y10S436/807; Y10S436/808; Y10S436/824; Y10S436/829
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
218 words
A device for use in an assay for detecting the presence of an analyte using a tracer having a particulate label comprising: a porous support having upper and lower surfaces and a test area on its upper surface; a binder attached to the test area; an absorptive layer in fluid communication with the porous support; and a porous flow control layer positioned between the lower surface of the porous support and the absorptive layer; wherein: the porous support has pore sizes sufficient to allow passage of liquid and any analyte and tracer not bound to the test area, the support area does not specifically bind the tracer, the test area has a surface area sufficiently large to support binder in a concentration whereby tracer specifically bound to the test area under assay conditions is visible, the porous flow control layer has unidirectional channels with their pore sizes smaller than those of the porous support and large enough to allow passage at controlled rates of liquid and any analyte and tracer not bound at the test area, and the porous support, the porous flow control layer and the absorptive layer cooperate to control flow of reagents through the porous support and to receive liquids and any analyte and tracer not specifically bound at the test area in absorptive layer.
Claim 2
Independent Claim
218 words
A device for use in an assay for detecting the presence of an analyte using a tracer having a particulate label comprising: a porous support having upper and lower surfaces and a test area on its upper surface; a binder attached to the test area; an absorptive layer in fluid communication with the porous support; and a porous flow control layer positioned between the lower surface of the porous support and the absorptive layer; wherein: the porous support has pore sizes sufficient to allow passage of liquid and any analyte and tracer not bound to the test area, the support area does not specifically bind the tracer, the test area has a surface area sufficiently large to support binder in a concentration whereby tracer specifically bound to the test area under assay conditions is visible, the porous flow control layer has unidirectional channels with their pore sizes smaller than those of the porous support and large enough to allow passage at controlled rates of liquid and any analyte and tracer not bound at the test area, and the porous support, the porous flow control layer and the absorptive layer cooperate to control flow of reagents through the porous support and to receive liquids and any analyte and tracer not specifically bound at the test area in absorptive layer.
Claim 3
Dependent Claim
59 words
The device of claim 1 further comprising a spacer layer positioned either between the porous flow controlling layer and the absorptive layer or between the porous support and the porous flow controlling layer and which allows liquids and any analyte and tracer not specifically bound at the test area to flow from the test area to the absorptive layer.
Claim 4
Dependent Claim
26 words
The device of claim 1 wherein the binder is attached to the test area in a concentration of at least 10 micrograms per cm 2 .
Claim 5
Dependent Claim
22 words
The device of claim 1 wherein the porous support is a nitrocellulose having a port size between 2 um and 12 um.
Claim 6
Dependent Claim
21 words
The device of claim 1 wherein the porous support is nitrocellulose having a pore size between 3 um and 5 um.
Claim 7
Dependent Claim
31 words
The device of claim 5 wherein the support, flow-control layer, and absorptive layer allow reagents to flow through the test area at a rate of at least 0.5 ml per minute.
Claim 8
Dependent Claim
28 words
A test kit comprising the device of claim 1 and a tracer having a particulate label that is visible when bound at the test area under assay conditions.
Claim 9
Dependent Claim
35 words
The test kit of claim 7 wherein the tracer is a specific binding species having a particulate label coupled to it and the particulate label is a sac and the sac contains a colored substance.
Claim 10
Dependent Claim
13 words
The test kit of claim 8 wherein the particulate label is a liposome.
Claim 11
Dependent Claim
13 words
The test kit of claim 9 wherein the colored substance is sulforhodamine B.
Claim 12
Dependent Claim
84 words
An assay for an analyte in a fluid sample comprising: providing the device of claim 1, contacting the test area of the device with the fluid sample and a tracer having a particulate label that is visible when bound at the test area under assay conditions such that any analyte and tracer not specifically bound at the test area flows from the test area into the absorptive layer and determining visibility of tracer specifically bound at the test area as a measure of analyte.
Claim 13
Dependent Claim
50 words
The assay of claim 11 wherein the analyte is one member of a specific binding pair, the binder is the other member of a specific binding pair and the tracer specifically binds to the analyte at sites not interfering with the specific binding reaction between the analyte and the binder.
Claim 14
Dependent Claim
23 words
The assay of claim 11 wherein the analyte and the tracer both specifically bind to the binder and compete for interfering binding sites.
Claim 15
Dependent Claim
18 words
The assay of claim 11 wherein the sample and tracer are contacted substantially simultaneously with the test area.
Claim 16
Dependent Claim
43 words
The assay of claim 11 wherein the sample is contacted with the test area, any analyte in the sample not specifically bound to the tracer flows through the device to the absorptive layer, and thereafter the tracer is contacted with the test area.
Claim 17
Dependent Claim
84 words
An assay for an analyte in a fluid sample comprising: providing the device of claim 6, contacting the test area of the device with the fluid sample and a tracer having a particulate label that is visible when bound at the test area under assay conditions such that any analyte and tracer not specifically bound at the test area flows from the test area into the absorptive layer, and determining visibility of tracer specifically bound at the test area as a measure of analyte.
Claim 18
Dependent Claim
50 words
The assay of claim 16 wherein the analyte is one member of a specific binding pair, the binder is the other member of a specific binding pair and the tracer specifically binds to the analyte at sites not interfering with the specific binding reaction between the analyte and the binder.
Claim 19
Dependent Claim
23 words
The assay of claim 16 wherein the analyte and the tracer both specifically bind to the binder and compete for interfering binding sites.
Claim 20
Dependent Claim
18 words
The assay of claim 16 wherein the sample and tracer are contacted substantially simultaneously with the test area.
Claim 21
Dependent Claim
43 words
The assay of claim 16 wherein the sample is contacted with the test area, any species in the sample not specifically bound to the tracer flow through the device to the absorptive layer, and thereafter the tracer is contacted with the test area.
References Cited (Backward Citations)
US4258001A
Cited
US4281061A
Cited
US4366241A
Cited
US4366241B1
Cited
US4472498A
Cited
US4703017A
Cited
US4703017C1
Cited
WO1985005451A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-23 | 1993-10-23 | 1994-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-23 | 1997-10-23 | 1998-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-23 | 2001-10-23 | 2002-04-24 | $7700.00 | Window Closed / Lapsed |