ELISA is used to test the presence of IgG antibodies in patients having food allergies. The main thing behind this testing is that high circulating levels of IgG antibodies are correlated with signs and symptoms of clinical food allergies. These tests help a doctor to analyze and pinpoint the food allergies in patients, so that they can avoid these foods. In this article we discuss some aspects of ELISA.
Enzyme-linked immunosorbent assay, in short ELISA, is a biochemical test used to detect the presence of antigens or antibodies in a sample. It is mainly used in immunology, the study of the body’s immune system.
The Principle: ELISA is based on the principle of antibody-antibody interaction. Antibody is immobilized on micro-plate wells and competition is induced between sample and labeled enzyme for binding sites. The unbound enzymes are washed away and chromogenic substrate is added to see the color. This color is read and analyzed in a spectrophotometer.
Uses of ELISA: ELISA test is mainly used to detect the substances with antigenic properties, especially the proteins. Hormones and bacterial antigens and antibodies are detected by ELISA tests. It is a tool for determining serum antibody concentrations.
ELISA in allergies:
ELISA has wide applications in the food industry, where potential food allergens such as milk, walnuts, almonds, peanuts and eggs are detected.
Types of ELISA: There are 4 types of ELISA:
- Indirect Elisa
- Sandwich Elisa
- Competitive Elisa
- Reverse Elisa
Each type of ELISA has its own advantages and disadvantages over the other. In general, ELISA tests have high sensitivity and specificity compared to other methods. The tests do not need radioisotopes or radioactive substances that are harmful for health.
