Method
The RAST test is a radioimmunoassay test to detect specific IgE antibodies to suspected or known allergens for the purpose of guiding a diagnosis about allergy. IgE is the antibody associated with Type I allergic response: for example, if a person exhibits a high level of IgE directed against pollen, the test may indicate the person is allergic to pollen (or pollen-like) proteins. A person who has outgrown an allergy may still have a positive IgE years after exposure.
The suspected allergen is bound to an insoluble material and the patient's serum is added. If the serum contains antibodies to the allergen, those antibodies will bind to the allergen. Radiolabeled anti-human IgE antibody is added where it binds to those IgE antibodies already bound to the insoluble material. The unbound anti-human IgE antibodies are washed away. The amount of radioactivity is proportional to the serum IgE for the allergen.
RAST are often used to test for allergies when:
• a physician advises against the discontinuation of medications that can interfere with test results or cause medical complications;
• a patient suffers from severe skin conditions such as widespread eczema or psoriasis; or
• a patient has such a high sensitivity level to suspected allergens that any administration of those allergens might result in potentially serious side effects.
Read more about this topic: RAST Test
Famous quotes containing the word method:
“Methinks the human method of expression by sound of tongue is very elementary, & ought to be substituted for some ingenious invention which should be able to give vent to at least six coherent sentences at once.”
—Virginia Woolf (1882–1941)
“Women stand related to beautiful nature around us, and the enamoured youth mixes their form with moon and stars, with woods and waters, and the pomp of summer. They heal us of awkwardness by their words and looks. We observe their intellectual influence on the most serious student. They refine and clear his mind: teach him to put a pleasing method into what is dry and difficult.”
—Ralph Waldo Emerson (1803–1882)
“Letters are above all useful as a means of expressing the ideal self; and no other method of communication is quite so good for this purpose.... In letters we can reform without practice, beg without humiliation, snip and shape embarrassing experiences to the measure of our own desires....”
—Elizabeth Hardwick (b. 1916)