RIDASCREEN® Gliadin competitive
Product Code R7011
Bruksområde:
RIDASCREEN® Gliadin competitive er en competitive enzyme
immunoassay (Elisa) for kvantitativ analyse av peptide fragmenter av prolaminer fra
hvete (gliadins), rug (secalin) og bygg (hordein) i øl, stivelse og stivelsessirup.
Den benyttede R5 monoclonal antikroppen gjenkjenner blant andre den toksiske sekvensen
QQPFP, som er uttrykt repeterende i prolamin molekylet og reagerer med amino syre sekvenser strukturert liknende. Testen er kalibrert til peptid sekvensen QQPFP.
Generell informasjon:
The use of wheat flour and gluten in foodstuffs is extremely common because of their heat stability and useful effects on e.g. texture, moisture retention and flavor. Gluten is a mixture of prolamin and glutelin proteins present in wheat, rye and barley. During chemical modification or enzymatic processes the whole molecules can be denaturated to small peptide fragments that may contaminate starches, syrups and beer for example.
Celiac disease is a permanent intolerance to repeatable toxic peptide motifs of
gluten that results in damage of the small intestine. The effects are reversible when
gluten is avoided in the diet. In the Codex Alimentarius "gluten-free" food is defined
as food having less than 200 ppm gluten. The proposed new Codex Standard for
gluten-free foods defines a maximum content of 20 ppm gluten in naturally glutenfree products and 200 ppm gluten in products rendered gluten-free. Several
countries have already implemented stricter limits.
The prolamins consist of several protein subgroups, which carry again a different
number of epitopes (approx. 33 amino acids). Repeating motifs of peptide fragments containing 5 to 30 amino acids can be toxic for celiac patients. Single
motifs cannot be detected by sandwich ELISA formats, because at least two
epitopes are necessary for a sandwich ELISA. Therefore this competitive ELISA
has been developed for the detection of small peptide fragments.
QQPFP is one of the peptide sequences, which occurs repeatedly on the epitopes
of the prolamins. The competitive ELISA is calibrated to that toxic amino acid
sequence. The antibody also reacts with similar sequences existing aside. In the
publication, A.A. Osman et al: A monoclonal antibody that recongnizes a potential
coeliac-toxic repetitive pentapeptide epitope in gliadins. Europ. J. Gastroenterol.
Hepatol., vol 13, 1189 (2001), the structures are shown, which react with the R5
antibody.
The test result is expressed in peptide equivalents.
Spesifikasjoner:
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Format:
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Microtiter plate with 96 wells (12 strips with
8 removable wells each)
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Standards:
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0 µg/ml (zero standard), 2.5 µg/ml, 5 µg/ml, 10 µg/ml,
20 µg/ml
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Sample preparation:
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homogenization and extraction
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Incubation time:
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40 min
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Detection limit:
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Limit of detection: 922 µg peptid / g food
Limit of quantification: 1250 µg peptid / g food
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Cross-reactions:
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The used monoclonal antibody recognizes toxic motifs
of gliadins from wheat and related prolamins from rye
and barley.
No cross-reaction with oats, corn, rice, millet,
buckwheat, Quinoa and Amaranth.
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Antall stk pr. pakke:96
Antall pakker pr kartong:1
Butikk 
