Walkthrough And Basic Definition Of Thyroid ELISA Kits

By Jocelyn Davidson


ELISA is a medical test used in the enclosure of laboratories to figure out if a person has any certain disease or condition. It is an abbreviation from Enzyme Linked Immunosorbent Assay, where it tests the presence of certain protein molecules in a sample. Its main purpose is for testing the immunity of a patient.

HIV tests are one of the many examples of ELISA. It detects antibodies which are connected to the virus that are inside the blood of the patient. As for thyroid glands, Thyroid ELISA kits are used in most laboratories for further studying the present protein molecules. With this, other various kits are existent depending on what use they are.

In general, ELISA is also used for tests in illegal drug use. It also helps determine the allergic reactions towards food for a person. It is widely used as a tool in plant pathology, and also in quality control check in some industries. How to determine this is through the intensity of the color change of each sample of the patient.

There are two most common types of ELISA tests. The indirect detects protein or the antibody and the example for this is as what was mentioned, HIV tests. The other one is the capture or sandwich. It detects the antigen by capturing them between two antibodies. The hormone human chorionic gonadotropin, or hCG, is detected using sandwich. One example of this would be pregnancy tests.

There are many ways to collect samples from the patient or donor. Two common ways are from blood or urine, which by now, you have already guessed, is taken during tests in clinics and hospitals. For blood samples, they are placed inside a test tube and sent to the laboratories for further analysis. Inside the laboratory, the actual testing would begin.

A centrifuge is used to make a blood serum which is used during the tests. The centrifuge would separate the compositions of the blood which are the cells and the plasma. A blood serum is the actual sample used in tests, and the clotting feature is actually taken out already.

There are enzyme substrate combinations that can be used for detection. The one enzyme used the most is Horseradish Peroxidase. This cleaves or separates the substrate molecules Ortho Phenylenediamine Dihydrochloride, or OPD, and Tetramethylbenzidine, or TMB, from each other. The result would be a yellow color when these two are separated. Then a plate reader is used to measure the optical density.

If the patient has already been determined to have a disease or condition, the samples of their blood or urine will have certain antibodies which will be the ones to react to the test. These antibodies will stick to the antigens, which these antigens are bonding agents for the entire test. A solution is used to wash away everything in it except for the antigens, or also the antibodies that are sticking to the antigens.

To get results through color changes, enzyme solutions would be added to the samples to get either a positive or a negative result. But there is a certain possibility for the test results to give a false positive. A false positive is when a sample has no infection or whatever but still gives a positive result. Even so, ELISA tests are reliable and considered to be a standard in the immunology community.




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