ALFA (Allergy Lateral Flow Assay)
ALFA (Allergy Lateral Flow Assay) is a rapid test for the determination of allergen specific Immunoglobulin E (sIgE) in human serum, plasma or whole blood
ALFA (Allergy Lateral Flow Assay) is a rapid test for the determination of allergen specific Immunoglobulin E (sIgE) in human serum, plasma or whole blood
The worldwide frequency of allergies increased significantly over the past decades. The term allergy is often used for type I hypersensitivity reactions (immediate type reactions), whose symptoms generally occur within 30-60 min after contact with the allergen. The most frequent symptoms are: hay fever (rhinitis), conjunctivitis, hives (urticaria), allergic asthma and as the most dangerous manifestation anaphylaxis (the anaphylactic shock). The allergens causing type I hypersensitivity reactions are mostly proteins derived from the natural environment e.g. plant pollen, animal hair, food, mites and insect venoms. The characteristic of type I allergies is the involvement of allergen specific immuno-globulins (antibodies) of class E (sIgE). Hence, the detection of sIgE is an important tool of modern allergy diagnostics.
ALFA is a screening test, which enables the user to perform an allergy test very fast and reliable. By choosing an appropriate allergen solutions a symptom based allergy diagnosis is possible. The test result are available in 20 minutes and are stated, when read with the LFA Reader, in Units/ml and classes according to the RAST classes. ALFA consist of one basis unit – the ALFA Basis Set – in combination with different, freely selectable allergen solutions, as single or mixed allergens (Screens) or as recombinant or native, highly purified allergens. ALFA Basis Set is available as single- (REF 1800010) and eight-strip cassette (REF 184000) – plus variable allergen solutions. (Download: Flyer ALFA)
To perform the test the patient´s sample is transferred to the sample application point of the Basis Set. Immediately afterwards, the desired allergen solution is applied. During incubation of 20 min the liquid is driven through the device by capillary flow. The allergen specific IgE of the sample binds specifically to its corresponding allergens of the allergen solution. The labelled allergens are retained at the test line (T) by a capture molecule. At the same time, the sIgE bound to the allergen is bound by an antibody coupled to colored particles (conjugate). The intensity of the color reaction at the test line is proportional to the amount of immune complexes consisting of ligand tagged allergens, sIgE and IgE specific conjugate. The signal intensity ranges from faintly pink (low titer of sIgE) to dark ruby (high titer of sIgE). Access conjugate, which is not bound at the test line, forms a dark ruby control line (C) during incubation. (Download: Instruction for use ALFA)
More than 150 freely selectable allergen solutions, as single or mixed allergens (Screens) or as recombinant or native, highly purified allergens are available for ALFA. All available allergens can be found in the current List of ALFA allergens and the current list of recombinant or native, highly purified allergens (Download: Flyer List ALFA Allergens, Flyer recombinante Allergene)
On the one hand the evaluation of ALFA can be done macroscopic, in which the intensity of the test line is proportional to the amount of bound sIgEs. The signal intensity ranges from faintly pink (low titer of sIgE) to dark ruby (high titer of sIgE). On the other hand ALFA can be evaluated with the help of the LFA (Lateral Flow Assay) Reader. The LFA Reader is a mobile measuring device for the quantitative evaluation and documentation of ALFA. The test result is stated in Units (U/mL) and classes, according to the RAST classes. For documentation the results can be printed, stored on an internal memory of the LFA Reader or exported. (Download: Flyer LFA Reader)
ALFA (Allergy Lateral Flow Assay) Total IgE is a rapid assay for the qualitative determination of total IgE in human serum, plasma or whole blood. ALFA Total IgE is designed as a screening test which allows a fast and easy detection of increased and highly increased Total IgE titers. Furthermore the test can be used in laboratories as validity check and confirmatory test, respectively. (Download: Flyer ALFA Total IgE) ALFA Total IgE consists of a test device – the ALFA Total IgE Basis Set – in combination with an Anti-IgE Solution. To perform the test the patient’s sample is transferred to the sample application point of the Basis Set. Immediately afterwards the Anti-IgE Solution is applied. During incubation time of 25-30 min the liquid is driven through the device by capillary flow. For interpretation of the result, the number of visible test lines and their intensity is assessed by an evaluation card (Download: instruction for use ALFA Total IgE) or with the LFA Reader in U/ml.