RIDASCREEN® Spezifisches IgE
Product Code A0249
Intended use:
For in-vitro diagnostic use. The RIDASCREEN® Spezifisches IgE test is an enzyme immunoassay (EIA) for the quantitative determination of specific IgE antibodies in human serum. When there is a suspected allergy according to the case history and in-vivo diagnostics, the test should be used for confirmation purposes. When the results of the in-vivo diagnostics are not in agreement with the case history, the test can also be used to determine specific IgE antibodies against allergens for the purpose of clarification.
General information:
The purpose of the immune system is to defend the body against
pathogenic bacteria, viruses and other microorganisms. The defence
reaction serves to protect the organism on initial contact with the
pathogens and immunise it on repeated contact. All Type I-allergic
reactions are preceded by an initial contact phase without symptoms
during which Class E specific antibodies (IgE antibodies) are formed.
On repeated contact with the allergens which trigger the reaction,
these IgE antibodies react with the allergens and lead to the release
of mediators (usually from mast cells or mastocytes) such as histamine,
leucotrien and prostaglandine etc. which lead to the symptoms of the
allergy.
When there is an allergic reaction, the allergens causing the
reaction can be identified by determining the specific IgE antibodies
in the serum. This method can also be used to determine sensitisations
without symptoms. The test is a cellulose-disc-based enzyme
allergo-sorbent test (EAST). All reagents (A0041 or A0040) listed under
Section 4 are validated using the allergen discs (A0049) from
R-Biopharm. When using these reagents with discs from other suppliers,
it is the duty of the user to carry out a validation test.
Test principle
The allergens are attached to the cellulose discs. In order to
carry out the test, the allergen discs are placed in the wells of a
microwell plate or are pre-coated according to the requirements of the
doctor. Patient sera, standard sera and negative and positive controls
are pipetted onto the allergen discs and incubated at 37 °C. During the
incubation, the allergy-specific IgE antibodies attach themselves to
the allergen. Material which does not attach is removed by washing.
After this, an anti-human IgE antibody, which is conjugated with
alkaline phosphatase, is also added. Any conjugate which is not
attached is removed by washing. Substrate is then added and is
dephosphorylated by the conjugated enzyme into a yellow product. The
intensity of the yellow colour is proportional to the quantity of
allergen-specific antibodies in the serum. A photometric measurement is
carried out at 405 nm using a reference wavelength of 620 nm. Some
allergens are attached to the cellulose disc via HSA (human serum
albumin). In this case, an additional HSA disc must be used to
determine the non-specific attachment of the allergen. The affected
allergens are labelled on the R-Biopharm AG code lists by the suffix
-HSA.
Specifications:
Format: |
|
Standards: | 0.35 - 100.00 IU IgE/ml |
Incubation time: | 135 min |
Cut-off: | The standard curve for RIDASCREEN® Spezifisches IgE is calibrated against the international reference preparation “2nd WHO IRP 75/502 for human IgE”. |
Sensitivity: | The
analytical sensitivity of the test kit in relation to the determination
of the standard material calibrated according to the WHO standard is
less than 0.24 IU/ml.
The diagnostic sensitivity is less than 0.35 IU/ml. |
Specificity: | A selection of representative allergens from 11 Allergen groups was tested on various sera in comparison to the systems from another supplier of systems for allergy in-vitro diagnostics. This yielded a specificity of 91,2 %. |