US5366868A
Expired / Lapsed
US
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Multilayer analytical element for assaying fructosamine
Assignee: Arkray Inc
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Filing: 1991-08-30
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Granted: 1994-11-22
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Expires: 2011-08-30
Abstract
Abstract A multilayer analytical element for assaying fructosamine, having a liquid-impermeable support, a buffer-containing layer which contains a buffer having pH of 8 to 12 formed on the support, a tetrazolium salt containing layer which is formed on the buffer-containing layer and, optionally, an intermediate layer interposed between the buffer-containing layer and the tetrazolium salt-containing layer to prevent contact of these two layers, which element assays fructosamine in a short time with good accuracy.
Inventors
- 👤 Hisashi Sakamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:22
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/66; Y; Y10; Y10S; Y10S435/00; Y10S435/805
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
72 words
A multilayer analytical element for assaying fructosamine, comprising a liquid-impermeable support, a buffer-containing layer which contains a buffer having a pH of 8 to 12 formed on said support, wherein said buffer-containing layer contains uricase, a tetrazolium salt-containing layer which is formed on said buffer-containing layer, and an intermediate layer interposed between said buffer-containing layer and said tetrazolium salt-containing layer to prevent contact of said buffer-containing layer and said tetrazolium salt-containing layer.
Claim 2
Dependent Claim
72 words
A multilayer analytical element for assaying fructosamine, comprising a liquid-impermeable support, a buffer-containing layer which contains a buffer having a pH of 8 to 12 formed on said support, wherein said buffer-containing layer contains uricase, a tetrazolium salt-containing layer which is formed on said buffer-containing layer, and an intermediate layer interposed between said buffer-containing layer and said tetrazolium salt-containing layer to prevent contact of said buffer-containing layer and said tetrazolium salt-containing layer.
Claim 3
Dependent Claim
44 words
The multilayer analytical element according to claim 1, wherein said tetrazolium salt contained in said tetrazolium salt-containing layer is at least one selected from the group consisting of 3,3'-[3,3'-dimethoxy- (1,1'-biphenyl)-4,4'-diyl ]-bis[2-(p-nitrophenyl)-5-phenyl-2H-tetrazolium chloride], 3,3'-[3,3'-dimethoxy-(1,1'-biphenyl)-4,4'-diyl]-bis[2,5-bis(p-nitrophenyl)-2H-tetrazolium chloride], 3,3'-(1,1'-biphenyl-4,4'-diyl)-bis(2,5-diphenyl-2H-tetrazolium chloride], 3-(p-iodophenyl)-2-(p-nitrophenyl)-5-phenyl-2H-tetrazolium chloride, 3-(4,5-dimethyl-2- thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide and 2,5-diphenyl-3-(1-naphthyl)-2H-tetrazolium chloride.
Claim 4
Dependent Claim
18 words
The multilayer analytical element according to claim 1, wherein said buffer has a pH of 8.5 to 10.5.
Claim 5
Dependent Claim
29 words
The multilayer analytical element according to claim 1, wherein said liquid-impermeable support is a material selected from the group consisting of a plastic film, paper, and a metal foil.
Claim 6
Dependent Claim
16 words
The multilayer analytical element according to claim 1, wherein said liquid-impermeable support is a plastic film.
Claim 7
Dependent Claim
15 words
The multilayer analytical element according to claim 1, wherein said buffer is a carbonate buffer.
Claim 8
Dependent Claim
16 words
The multilayer analytical element according to claim 1, wherein said buffer-containing layer further comprises a binder.
Claim 9
Dependent Claim
15 words
The multilayer analytical element according to claim 7, wherein said binder is a hydrophilic polymer.
Claim 10
Dependent Claim
27 words
The multilayer analytical element according to claim 8, wherein said hydrophilic polymer is a member selected from the group consisting of polyvinylpyrrolidone, hydroxypropylcellulose, methylcellulose, polyacrylamide, and gelatin.
Claim 11
Dependent Claim
16 words
The multilayer analytical element according to claim 1, wherein said intermediate layer comprises a binder resin.
Claim 12
Dependent Claim
16 words
The multilayer analytical element according to claim 10, wherein said binder resin is hydroxypropylcellulose or polyvinylpyrrolidone.
Claim 13
Dependent Claim
26 words
The multilayer analytical element according to claim 1, wherein said tetrazolium salt-containing layer is formed by impregnating a solution of said salt in a porous matrix.
Claim 14
Dependent Claim
34 words
The multilayer analytical element according to claim 12, wherein said porous matrix is a member selected from the group consisting of a filter paper, a woven fabric, a knit fabric, and a membrane filter.
Claim 15
Dependent Claim
34 words
The multilayer analytical element according to claim 1, wherein said buffer-containing layer has a wet thickness of 250 μm or less and said tetrazolium salt-containing layer has a thickness of 300 μm or less.
Claim 16
Dependent Claim
32 words
The multilayer analytical element according to claim 14, wherein said buffer-containing layer has a wet thickness of about 200 μm and said tetrazolium salt-containing layer has a thickness of about 250 μm.
Claim 17
Dependent Claim
21 words
The multilayer analytical element according to claim 1, wherein said intermediate layer has a wet thickness of 200 μm or less.
Claim 18
Dependent Claim
20 words
The multilayer analytical element according to claim 16, wherein said intermediate layer has a wet thickness of about 150 μm.
Claim 19
Dependent Claim
67 words
The multilayer analytical element according to claim 1, wherein said liquid-impermeable support is an opaque polyethylene terephthalate film, said buffer-containing layer is formed by mixing sodium carbonate, sodium hydrogencarbonate, water, and a polyvinylpyrrolidone polymer, said tetrazolium salt-containing layer is a cotton or polyester fabric impregnated with a mixture formed by mixing 3,3'-[3,3'-dimethoxy-(1,1'-biphenyl)-4,4'-diyl]-bis[2-(p-nitrophenyl)-5-phenyl2-H-tetrazolium chloride], methanol, and water, and said intermediate layer is formed by mixing hydroxypropylcellulose and isopropanol.
Claim 20
Dependent Claim
66 words
The multilayer analytical element according to claim 1, wherein said liquid-impermeable support is an opaque polyethylene terephthalate film, said buffer-containing layer is formed by mixing sodium carbonate, sodium hydrogencarbonate, water, a polyvinylpyrrolidone polymer, and uricase, said tetrazolium salt-containing layer is a polyester fabric impregnated with a mixture formed by mixing 3,3'-[3,3'-dimethoxy-(1,1'-biphenyl)-4,4'-diyl]-bis[2-(p-nitrophenyl)-5-phenyl-2H-tetrazolium chloride], methanol, and water, and said intermediate layer is formed by mixing hydroxypropylcellulose and isopropanol.
Claim 21
Dependent Claim
51 words
A method for assaying fructosamine, comprising the steps of: (a) placing a sample of body fluid on said multilayer analytical element of claim 2; (b) measuring the amount of color developed; and (c) determining the amount of fructosamine by comparing the amount of color developed to values on a standard curve.
Claim 22
Dependent Claim
21 words
The method according to claim 20, wherein said measuring is conducted by monitoring the reflectance from said sample of body fluid.
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| 3.5 Years (Year 4) | 1997-11-21 | 1998-05-23 | 1998-11-22 | $2000.00 | Window Closed / Lapsed |
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