Lateral-flow assay device with filtration flow control

Patent metadata

Field	Value
Publication number	US-11033896-B2
Application number	US-201514817946-A
Country	US
Kind code	B2
Filing date	Aug 4, 2015
Priority date	Aug 8, 2014
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

A lateral-flow assay device includes a substrate with a sample addition zone and a fluid flow path. A cover supports a filter having a portion contacting the substrate to create a contact area that at least partly overlaps the sample addition zone. Another portion extends from the contact portion to the supported periphery of the filter to define with the substrate a reservoir configured to retain the filtrate by capillary pressure between the substrate and the extending portion. The reservoir volume is based on an acute angle formed between the substrate and the extending portion of the filter and on a fluid meniscus of the filtrate. The filter and sample addition zone are configured to provide capillary pressure drawing the filtrate from the reservoir to the sample addition zone. Methods for controlling flow characteristics in a lateral-flow assay device are also described.

First claim

The invention claimed is:

1. A lateral-flow assay device for a sample, the device comprising:
a) a substrate having a sample addition zone and a fluid flow path through which a filtrate flows under capillary action away from said sample addition zone;
b) a cover arranged over the substrate and having an aperture defining a metering port configured to receive the sample;
c) a filter having a concave shape and supported peripherally within the aperture and configured to permit at least a portion of the sample to pass therethrough as the filtrate, the supported filter having:
i) at least one contact portion in direct contact with the substrate to create a contact area that at least partly overlaps the sample addition zone; and
ii) another portion that extends at an acute angle between the at least one contact portion and the supported periphery of the filter to define a space between the extending portion of the filter and the substrate, the space configured to retain the filtrate by capillary pressure between the substrate and the extending portion of the filter; and

d) one or more projecting member(s) each including a tip arranged to press the at least one contact portion of the filter against the substrate,
wherein, when the filtrate passes through the filter, the filtrate forms a reservoir within the space between the extending portion of the filter and the substrate, the reservoir defined by a volume based on the acute angle formed between the substrate and the extending portion of the filter and based on a fluid meniscus of the filtrate, and wherein the filter and sample addition zone are configured to provide a capillary pressure drawing the filtrate from the reservoir to the sample addition zone, and
wherein the sample addition zone is smaller than the contact area.

2. The device as recited in claim 1 , wherein the sample addition zone extends laterally beyond the contact area.

3. The device as recited in claim 1 , wherein the contact area extends laterally beyond the sample addition zone.

4. The device as recited in claim 1 , wherein the at least one projecting member eccentrically engages a portion of the supported filter.

5. The device as recited in claim 1 , wherein at least one of the projecting member(s) comprises a nub.

6. The device as recited in claim 1 , wherein at least one of the projecting member(s) includes a cantilevered portion supporting the tip with respect to the cover.

7. The device as recited in claim 1 , wherein the substrate includes a plurality of microposts extending upwardly from the surface toward the cover in the sample addition zone, the microposts having heights, diameters and reciprocal spacing between the microposts that induce lateral capillary flow upon the application of filtrate thereto.

8. The device as recited in claim 1 , further including at least one reagent zone disposed along the fluid flow path downstream of the sample addition zone, the reagent zone retaining at least one detection material.

9. The device as recited in claim 1 , further including a detection zone disposed along the fluid flow path downstream of the sample addition zone and including detection material responsive to an analyte to produce a detectable signal.

10. The device as recited in claim 1 , wherein the filter is circular.

11. The device as recited in claim 1 , wherein the contact area is smaller than the filter.

12. The device as recited in claim 1 , wherein the tip eccentrically engages the filter.

13. The device as recited in claim 1 , wherein at least one of the projecting member(s) is arranged to define at least a first portion and an second portion of the filter, the first portion of the filter forming a larger angle with the substrate than does the second portion of the filter.

14. The device as recited in claim 13 , wherein the first portion of the filter is upstream of the second portion of the filter with respect to the fluid flow path.

15. The device as recited in claim 1 , wherein the filter is defined by an angle extending from the contact portion to an edge of the aperture, the device further comprising at least one engagement feature that controls the angle.

16. The device as recited in claim 15 , wherein the engagement feature includes a projecting member.

17. A lateral-flow assay device for a sample, the device comprising:
a) a substrate having a sample addition zone and a fluid flow path through which a filtrate flows under capillary action away from said sample addition zone;
b) a cover arranged over the substrate and having an aperture defining a metering port configured to receive the sample;
c) a filter having a concave shape and supported peripherally within the aperture and configured to permit at least a portion of the sample to pass therethrough as the filtrate, the supported filter having:
i) at least one contact portion in direct contact with the substrate to create a contact area that at least partly overlaps the sample addition zone; and
ii) another portion that extends at an acute angle between the at least one contact portion and the supported periphery of the filter to define a space between the extending portion of the filter and the substrate, the space configured to retain the filtrate by capillary pressure between the substrate and the extending portion of the filter; and

d) one or more projecting member(s) including a tip arranged to press the at least one contact portion of the filter against the substrate,
wherein, when the filtrate passes through the filter, the filtrate forms a reservoir within the space between the extending portion of the filter and the substrate, the reservoir defined by a volume based on the acute angle formed between the substrate and the extending portion of the filter and based on a fluid meniscus of the filtrate, and wherein the filter and sample addition zone are configured to provide a capillary pressure drawing the filtrate from the reservoir to the sample addition zone.

Assignees

• Ortho Clinical Diagnostics Inc

Inventors

• Ding Zhong
• Scalice Edward R
• Hosimer Philip C

Classifications

• G01N33/54388 Primary

  based on lateral flow · CPC title

• B01L2300/0681

  Filter · CPC title

• B01L3/5023 Primary

  with a sample being transported to, and subsequently stored in an absorbent for analysis · CPC title

• B01L2400/0406

  capillary forces · CPC title

• G01N33/558

  using diffusion or migration of antigen or antibody {(immunochromatographic test strips G01N33/54387)} · CPC title