There are several ways to test for HIV, but one of the most common, if not the most common, of them all is the ELISA Test. ELISA stands for Enzyme-Linked Immunosorbent Assay. It is an HIV testing method that detects the presence of antigens or antibodies in a patient’s body.
The Five Types of ELISA Test
ELISA test is divided into five types, according to five different enzymes used in the testing procedure. They are the:
- Competitive ELISA
- Direct ELISA
- Indirect ELISA
- Multiplex ELISA
- Sandwich ELISA
All methods are done the same way, and HIV patients can undergo at least one of those, depending on what his or her doctor advises.
Steps On ELISA Testing
ELISA test is an HIV test that is widely used around the world. Once a blood sample of the patient has been taken, the test is done in a pathology laboratory using a few laboratory tools and equipment. Let me share how it is done step-by-step.
- First, a patient’s blood sample is collected so that serum from the blood can be acquired.
- Second, an ELISA plate is prepared with pure, inactive antigens.
- Third, the serum from the patient’s blood sample will then be placed on the ELISA plate with the pure, inactive antigens.
Fourth, a person who is positive with HIV should have HIV antibodies in his or her serum. So when the serum is placed on the ELISA antigen plate, the HIV antibodies should bind with the antigens.
- Fifth, the plate is then washed using a certain solution that removes unnecessary particles around the antigen-antibody matter.
- Finally, the remaining antigen-antibody matter is treated with an enzyme that will cause a color change if a person is positive for HIV.
Accuracy of the ELISA Test
ELISA tests have proven that they are reliable when it comes to telling whether a person has HIV or not. They are widely used by a lot of medical practitioners around the world, so rest assured that their accuracy is very high.
What doctors usually do is to conduct a few more tests once a person is tested positive for HIV. They will do another ELISA test or try another HIV testing method such as the Western Blot test. If the Western Blot test also gives back a positive result, then that person really has HIV.