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In time for this year's AACC in Orlando next week this edition of the DIARECT newsletter presents current information on DIARECT's new product developments - two parameters belonging to the group of intestinal autoimmune markers: Intrinsic Factor (IF), the key target for monitoring pernicious anemia is now available as human recombinant antigen, and we are also announcing the release of two gliadin preparations, protein-chemically fine-tuned for optimal EIA detection of IgA as well as IgG antibodies to gliadin determinants.
We are pleased again to present SurModics' contribution on their newest product developments for optimized stabilization of microspheres as well as microarray based assays.
By the way, since starting our first DIARECT newsletter two months ago we have received considerable feed-back. Thank you for your helpful and encouraging comments confirming our idea of this information forum for our international clients and cooperation partners.
We will be at the upcoming AACC presenting together with our US distributor, Rocky Mountain Diagnostics (booth number 2432). We are looking forward to seeing you there.
Pleasant reading!
Your DIARECT team
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Intrinsic Factor Cat.No. 16700 |
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Intrinsic Factor / New human auto-antigen, finally expressed the recombinant eukaryotic way!
Circulating antibodies against gastric intrinsic factor (IF) are highly specific and of high diagnostic relevance for pernicious anemia. Two types of clinically important autoantibodies can be measured (i) so-called blocking antibodies which prevent the binding of vitamin B12 to the IF molecule; they are present in >50% of all patients with Biermer's anemia. (ii) Other types of antibodies to IF may interfere with the binding of the IF-Vit B12 complex to the ileal receptor and are less common and sensitive.
Because of the mediocre purity of animal IF antigen available, RIA has for many years been the method of choice even though it is rather prone to false positive results as a consequence of high, therapeutic Vit B12 concentration in the serum. EIA is not influenced by high, therapeutic Vit B12 and, therefore, is more sensitive than RIA and can - in addition - detect both types of antibodies, a well known fact already pointed out by Humbel and Pierrard 15 years ago.
We have now closed the gap in high-quality antigen supply with the recombinant expression of human IF in the baculovirus/Sf9 system. As in the natural cellular situation our recombinant human IF passes the endosomal pathway via Golgi glycosylation and is secreted into the culture medium. During the thorough and careful purification process the depletion of cobalamin is achieved, which exposes all relevant epitopes accessible for autoantibody binding. DIARECT Intrinsic Factor will open up the perspective of improved diagnostic devices whenever it comes to in-vitro testing of patients with the risk of Biermer's anemia.
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Gliadin (IgA) Cat.No. 17100 / Gliadin (IgG) Cat.No. 17200 |
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In vitro diagnostic regimes for celiac disease (CD) have been considerably meliorated by the implementation of gliadin antibody test systems and have been further improved with the availability of recombinant human tissue-type transglutaminase (tTG) as a diagnostic target. Even if tTG has proved to be superior in terms of specificity over gliadin antibodies, the latter are still very frequently an integral part of routine CD diagnosis.
To further enhance clinical specificity of gliadin antibodies tests (especially in the ELISA format) DIARECT now presents two gliadin antigen preparations specifically tuned for IgA and IgG antibodies measurement, respectively, both of which exhibit an enhanced potential to avoid false positive results.
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Description of New Products for Microspheres & Microarrays |
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StabilCoat® Plus and StabilGuard® Choice Stabilizers for Microspheres & Microarrays
StabilCoat® Plus and StabilGuard® Choice Stabilizers provide optimum performance for both microsphere and microarray applications. StabilGuard® Choice is completely synthetic and therefore does not contain any protein components. Both products contain a mercury-free, azide-free preservative.
For microspheres, these products
* improve stability of proteins bound to microspheres in solution
* protect the activity of proteins while blocking nonspecific binding sites
* prevent aggregation, even after long-term storage
For microarrays, these products
* improve protein array performance by increasing signal, reducing background and improving sensitivity
* effectively preserve the conformation and activity of array proteins stored long-term in a dried state.
Microsphere Stabilizers
Microarray Reagents
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