In most cases the test is performed on blood drawn from a vein. The blood is checked for the presence of antibodies to HIV. Other body fluids can also be tested to screen for HIV. These include:
Oral Fluid Tests. These tests use oral fluid (not saliva) that is collected from the mouth using a special collection device.
Urine Tests. These tests use urine instead of blood.
The sensitivity and specificity (accuracy) of the oral and urine tests are less than that of the traditional blood tests. Several blood tests being used more commonly detect both antibodies and antigen (part of the virus itself), which can find HIV as soon as 3 weeks after exposure.
Rapid Tests: A rapid test is a screening test that produces very quick results (approximately 20-60 minutes).
Home Testing Kits: The Home Access HIV-1 Test System can be found at most local drug stores. It is not a true home test, but a home collection kit. The testing procedure involves pricking a finger with a special device, placing drops of blood on a specially treated card, and then mailing the card in to be tested at a licensed lab.
If any of these tests is positive, follow-up diagnostic testing is always done to confirm the results.