Friday, October 10, 2014

Walkthrough And Basic Definition Of Thyroid ELISA Kits

By Jocelyn Davidson


ELISA is short for enzyme linked immunosorbent assay. This is a diagnostic medical test to see if there is any present antibody or antigen in the body of a person. Its purpose is for calibrating the immunity of a person in terms of diseases and viruses. It identifies the protein concentration in the bodily fluids of a person.

An example for this would be for HIV testing. It looks for the certain antibodies which is related to the HIV virus within the blood. In regards to the thyroid glands, what is used are Thyroid ELISA kits, which are very common. Other testing kits are available as well for other parts of the body.

Finding out if you have any specific food allergy is also done using this test. It may be used for testing if a patient is using illegal drugs. Generally, it is a tool for plant pathology and quality control check for certain industries. The calibration or reading is through how vibrant the color is and its changes after each sample is tested.

There are a few other ELISA tests that are available and existent, but the two common types are the indirect and capture. The indirect detects a certain protein or antibody, and an example for this is the HIV testing. The capture, also known as the sandwich, detects another protein which is the antigen, then captures it between two antibodies. An example is pregnancy tests where the detection of hCG or human chorionic gonadotropin is seen.

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.

The human blood samples inside the test tubes will be placed in a centrifuge to separate the different parts of it and for it to get a blood serum. A blood serum is a sample that has the clotting feature taken out of it. The high speed from the centrifuge separates the cells and plasma, making it easier to extract the serum.

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.

When the patient is thought to have a known disease or condition, the blood or urine sample will have specific antibodies which will react to the testings. These antibodies will latch itself to the antigens which are the specific bonding agents in the test. After that, the samples will be washed with a solution in order for it to remove everything else except for the antigens or also the antibodies.

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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