Patent EP0051985A2 successfully refreshed from Google Patents.
EP0051985A2
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EP
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Immunoassay of proteins
Assignee: INTERNATIONAL INSTITUTE OF CELLULAR AND MOLECULAR
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Filing: 1981-11-05
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Granted: —
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Expires: 2001-11-05
Abstract
Abstract In the immunoassay of a particular protein in a biological fluid, there is frequently interference in the assay by other proteins present in the fluid, e.g. by complement factors or antibodies in human serum.The interference so caused can be avoided by subjecting the fluid to protein-digestion, using for example an enzyme such as pepsin, as a result of which the particular protein of interest, or a fragment thereof, can be assayed without interference by the other proteins. Also, radioallergosorbent tests for particular IgE antibodies can be improved in sensitivity and accuracy, by subjecting the absorbed IgE to enzymic digestion, and then assaying a fragment thereof.
Inventors
- 👤 Carl-Gustav M. Magnusson
- 👤 Pierre L. Masson
- 👤 Daniel Collet-Cassart
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 17:09
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/563; Y; Y10; Y10S; Y10S436/00; Y10S436/825
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
91 words
A method of immunoassay of a selected protein in a liquid sample also containing one or more other non-selected proteins, which comprises reducing or avoiding interference from said other proteins by mixing with the liquid sample a protein-digesting reagent, and allowing protein digestion to occur under conditions such that the said selected protein provides, in the resulting mixture, an antigenic determinant which is distinctive only thereof in the said mixture; and thereafter assaying the said antigenic determinant and determinining therefrom the amount of said selected protein present in the liquid sample.
Claim 2
Independent Claim
91 words
A method of immunoassay of a selected protein in a liquid sample also containing one or more other non-selected proteins, which comprises reducing or avoiding interference from said other proteins by mixing with the liquid sample a protein-digesting reagent, and allowing protein digestion to occur under conditions such that the said selected protein provides, in the resulting mixture, an antigenic determinant which is distinctive only thereof in the said mixture; and thereafter assaying the said antigenic determinant and determinining therefrom the amount of said selected protein present in the liquid sample.
Claim 3
Dependent Claim
63 words
A method according to claim 1, wherein the said reagent is an enzyme and said selected protein is broken down by said enzyme to form a fragment thereof which is antigenically distinctive only of said selected protein in the mixture; and wherein the said distinctive fragment is assayed by reacting it with the F(ab) region of an antibody which is selectively reactive therewith.
Claim 4
Dependent Claim
30 words
A method according to claim 2, wherein the said distinctive fragment only is assayed by reacting it with the F(ab) region of an antibody raised against the said distinctive fragment.
Claim 5
Dependent Claim
19 words
A method according to claim 2 or 3, wherein the fragment is assayed by reacting it with whole antibody.
Claim 6
Dependent Claim
23 words
A method according to claim 2 or 3, wherein the fragment is assayed by reacting it with F(ab') 2 fragments of an antibody.
Claim 7
Dependent Claim
48 words
A method according to claim 1, wherein the said digestion is effected under conditions such that the said other proteins are fragmented but the selected protein is substantially unaffected and the antigenic determinant thereof in the digested mixture is the same as that of the whole protein itself.
Claim 8
Independent Claim
42 words
A method according to any preceding claim, wherein the antigenic determinant provided by said selected protein is assayed by a particle agglutination technique in which the amount of said selected protein is determined from the extent of agglutination of finely divided particles.
Claim 9
Independent Claim
15 words
A method according to any preceding claim, wherein the liquid sample is a biological fluid.
Claim 10
Independent Claim
20 words
A method according to any preceding claim, wherein the protein-digesting agent is an enzyme selected from pepsin, papain and trypsin.
Claim 11
Independent Claim
125 words
A method of assaying a selected protein in a biological fluid sample also containing one or more other non-selected proteins, whereby interference in the assay from said other proteins is avoided and the specificity and accuracy of the assayed improved, which method comprises: a) contacting said sample with an inert solid support material bearing a reagent which selectively binds only to said selected protein in the sample; b) removing said support material from the sample, the support carrying therewith the selected protein; c) subjecting the removed selected protein to digestion under conditions such as to form therefrom an antigenically distinctive fragment of the said protein; and d) assaying the said fragment and therefrom determining the a mount of said selected protein in the liquid sample.
Claim 12
Independent Claim
125 words
A method of assaying a selected protein in a biological fluid sample also containing one or more other non-selected proteins, whereby interference in the assay from said other proteins is avoided and the specificity and accuracy of the assayed improved, which method comprises: a) contacting said sample with an inert solid support material bearing a reagent which selectively binds only to said selected protein in the sample; b) removing said support material from the sample, the support carrying therewith the selected protein; c) subjecting the removed selected protein to digestion under conditions such as to form therefrom an antigenically distinctive fragment of the said protein; and d) assaying the said fragment and therefrom determining the a mount of said selected protein in the liquid sample.
Claim 13
Dependent Claim
39 words
A method according to claim 10, wherein the selected protein is a particular IgE antibody and the said other proteins include at least one other IgE which is incapable of binding to the reagent on said inert solid support.
Claim 14
Dependent Claim
31 words
A method according to claim 11, wherein.the said inert solid support material bearing a reagent is a sheet of inert material bearing an allergen against which the particular IgE is directed.
Claim 15
Dependent Claim
42 words
A method according to claim 10,11 or 12, wherein in step (d), the said fragment is assayed by reaction with the F(ab) region of an antibody reactive therewith, and wherein the extent of such reaction is measured by a particle agglutination technique.
Claim 16
Dependent Claim
16 words
A method according to claim 13, wherein the fragment is assayed by reaction with whole antibody.
Claim 17
Dependent Claim
20 words
A method according to claim 13, wherein the fragment is assayed by reaction with F(ab') 2 fragments of an antibody.
Claim 18
Independent Claim
21 words
A method according to any of claims 10 to 13, wherein in step (c) the digestion is effected by an enzyme.
Claim 19
Independent Claim
126 words
A method of assaying a selected protein in a liquid sample also containing one or more other non-selected proteins, whereby interference from said other proteins is reduced or avoided, which comprises the steps of: a) preliminarily subjecting samples of said selected protein to enzymatic digestion under varying conditions, separating the protein fractions produced and determining the conditions of digestion which result in production of an antigenically distinctive fragment of said selected protein; and thereafter: b) subjecting said liquid sample to enzymatic digestion utilising said conditions of digestion determined in step (a); c) stopping said digestion; and d) assaying the resulting mixture to determine therein the amount of antigenically distinctive fragment of said selected protein, and therefrom determining the amount of said protein in the liquid sample.
Claim 20
Independent Claim
126 words
A method of assaying a selected protein in a liquid sample also containing one or more other non-selected proteins, whereby interference from said other proteins is reduced or avoided, which comprises the steps of: a) preliminarily subjecting samples of said selected protein to enzymatic digestion under varying conditions, separating the protein fractions produced and determining the conditions of digestion which result in production of an antigenically distinctive fragment of said selected protein; and thereafter: b) subjecting said liquid sample to enzymatic digestion utilising said conditions of digestion determined in step (a); c) stopping said digestion; and d) assaying the resulting mixture to determine therein the amount of antigenically distinctive fragment of said selected protein, and therefrom determining the amount of said protein in the liquid sample.
Claim 21
Dependent Claim
65 words
A method according to claim 17, wherein the liquid sample is human serum; the enzyme is pepsin; and wherein in step (d) the said fragment is assayed by reaction thereof with the F(ab) region of an antibody raised against the fragment, in the presence of finely divided particles the amount of fragment being determined by measurement of the extent of agglutination of the said particles.
Claim 22
Dependent Claim
20 words
A method according to claim 18, wherein the fragment is assayed by reaction with whole antibody raised against the fragment.
Claim 23
Dependent Claim
24 words
A method according to claim 18, wherein the fragment is assayed by reaction with F(ab') 2 fragments of the antibody raised against the fragment.
References Cited (Backward Citations)
No citation records indexed.
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