US4781890A
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Multilayer chemical analytical element
Assignee: Fujifilm Holdings Corp
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Filing: 1987-02-05
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Granted: 1988-11-01
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Expires: 2007-02-05
Abstract
Abstract A multilayer chemical analytical element is employable in quantitative analysis of analyte in a biological fluid such as blood. The element consists of a porous spreading layer, a light-blocking layer and a reagent layer on a water-impermeable light-transmissive support in order. The light-blocking layer contains a titanium dioxide fine powder with no provision of aluminum oxide compound or silicon oxide.
Inventors
- 👤 Fuminori Arai
- 👤 Kenichiro Yazawa
- 👤 Harumi Katsuyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:15
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/26; G; G01; G01N; G01N31/00; G01N31/22; G01N33/00; G01N33/48; G01N33/50; G01N33/52; G01N33/525; Y; Y10; Y10S; Y10S435/00; Y10S435/805; Y10T; Y10T436/00; Y10T436/14; Y10T436/142222; Y10T436/143333; Y10T436/144444; Y10T436/25; Y10T436/25125
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
70 words
In a multilayer chemical analytical element which includes a porous spreading layer, a light-blocking layer and a reagent layer on a water-impermeable light-transmissive support in order, wherein the improvement comprises having said light-blocking layer contain a titanium dioxide fine powder having neither an aluminum oxide compound nor silicon oxide, the element containing a compound having a cation which is capable of forming a sparingly water soluble salt with flourine anion.
Claim 2
Dependent Claim
70 words
In a multilayer chemical analytical element which includes a porous spreading layer, a light-blocking layer and a reagent layer on a water-impermeable light-transmissive support in order, wherein the improvement comprises having said light-blocking layer contain a titanium dioxide fine powder having neither an aluminum oxide compound nor silicon oxide, the element containing a compound having a cation which is capable of forming a sparingly water soluble salt with flourine anion.
Claim 3
Dependent Claim
35 words
The analytical element according to claim 1, wherein said reagent layer contains peroxidase and a hydrogen peroxide indicator which is capable of showing a detectable change in the presence of said peroxidase and hydrogen peroxide.
Claim 4
Dependent Claim
24 words
The analytical element according to claim 1, wherein said cation is a cation selected from the group consisting of divalent calcium and divalent magnesium.
Claim 5
Dependent Claim
28 words
The analytical element according to claim 1, wherein said titanium dioxide fine powder is in a crystalline form selected from the group consisting of anatase, rutile and brookite.
Claim 6
Dependent Claim
14 words
The analytical element according to claim 1, wherein said light-blocking layer includes a surfactant.
Claim 7
Dependent Claim
14 words
The analytical element according to claim 5, wherein said surfactant is a non-ionic surfactant.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-01 | 1992-05-02 | 1992-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-01 | 1996-05-02 | 1996-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-01 | 2000-05-02 | 2000-11-01 | $7700.00 | Window Closed / Lapsed |