FastCheckPOC - Rapid Allergy Test

How to perform a test

 how to perform a test - fastcheck 1.39 Mb

Frequently Asked Questions

• What does “Screening Test” mean?
• Can I use serum instead of whole blood?
• Why does the backround change from pink to dark-violet?
• Why does the device leak?
• Why don’t the controls show up clearly?
• Where do the white spots come from on the test membrane?
• Why don’t I get any results at all?
• Why don’t allergens appear positive that are expectedly positive?
• Why do unexpected allergens appear as positive?
• How can allergens that are confirmed by anamnesis be positive but weak?
• How can the test be negative when allergic problems have been diagnosed in the anamnesis?
• Why does the FastCheckPOC not confirm certain positives from the last skin prick test?

What does “Screening Test” mean?

Can I use serum instead of whole blood?

Why does the background change from pink to dark-violet?

• It is essential to exactly follow the instructions of use especially regarding all washing and rinsing steps as well as incubation times.
• Test membrane has not been washed properly.
• Test membrane has not been thoroughly moistened before applying the blood sample mixture.
• At least 100 µl of whole blood has to be applied, but no more than 500 µl.
• Read-out has not been done in time.
• After stopping the test reaction results have to be read within 10 minutes max.
• The test kit was not stored according to the instructions: Store at 4°C.
  

Why does the device leak?

• The device has not been properly closed. Press down the device lid tightly until you hear and feel a clicking. Make sure that you see no gap between the lid and the body of the device.
• What if the test membrane is not in place correctly?
  Wearing rubber gloves the test membrane might be adjusted inside the incubation chamber of the device. Make sure that the raw edge of the membrane is located to lower right.
  

Why don’t the controls show up clearly?

• Too little blood sample was applied. (<100 µl).
• The incubation times were not met.
• The test components were not stored at 4°C.
• The blood sample mixture was not evenly distributed across the entire test membrane.

Where do the white spots come from on the test membrane?

Air bubbles were not removed from the test membrane prior to incubation. It is important that the Sample mixture and all reagents and buffers cover the entire membrane area.If air bubbles become visible, move device in an upright position or draw fluid back into syringe and fill device again. Smaller bubbles (max. 0,5 mm diameter) at the edge of the membrane do not interfere with the test. Membrane areas that were not affected by bubbles can still be evaluated.

Why don’t I get any results at all?

• The test membrane was turned upside down.
• One or more steps of the test were omitted or were carried out in wrong order.
  

Why don’t allergens appear positive that are expectedly positive?

• The Cut-off level of specific IgE has not been reached (cut-off corresponds to RAST class 2).
• Several months have gone since th last laboratory or skin prick test was performed with the patient.
• Allergy status might have changed.
• In rare cases the amount of allergen-specific IgE might decrease as a consequence of therapeutic treatment (medication, de-sensi¬tisation etc.)
  

Why do unexpected allergens appear as positive?

• Cross reactions might occur, e.g. cross reactions between banana, ficus and latex.
• Why do I get positives that are not confirmed by anamnesis?
  The patient might have developed a tolerance against the particular allergen (e.g. specific IgG antibody against the allergen in question).
  

How can allergens that are confirmed by anamnesis be positive but weak?

• Besides sIgE-antibodies the patient has also developed sIgG-antibodies. The latter might prevent sIgE from binding to allergens on the membrane.
• However, an allergy exists though sIgG-antibodies do not have to do anything with the allergy.
• The patient has an unusually high overall IgE level; the detection antibody is entirely absorbed, hence all results become weaker than with lower overall IgE levels.
  

How can the test be negative when allergic problems have been diagnosed in the anamnesis?

• If both the food and the inhalation allergen version of the FastCheckPOC tests give negative results the patient might be allergic to allergens that are not covered by the current FastCheckPOC panels.
• If the FastCheckPOC food test is negative although the patient suffers gastrointestinal problems, a food intolerance diagnosis (irritable bowel syndrom, IBS) should be done.
• FastCheckPOC detects specific IgE. Besides „allergy of immediate type“ (type-I) caused by specific IgE, other allergy types exist that are independend of IgE. These cannot be detected by the FastCheckPOC.
  

Why does the FastCheckPOC not confirm certain positives from the last skin prick test?

The prick test might lead to reactions not caused by an allergy (i.e., the presence of of specific IgE antibodies); eamples: Skin disorders, pseudo-allergic reactions, emotional excitement, reaction on inflammations etc.

• Tel  00800 16310410
• Fax 00800 16310411