A Western blot test is typically used to confirm a positive HIV diagnosis. During the test, a

small sample of blood is taken and it is used to detect HIV antibodies, not the HIV virus

itself. The Western blot test separates the blood proteins and detects the specific proteins

(called HIV antibodies) that indicate an HIV infection. The Western blot is used to confirm a

positive ELISA, and the combined tests are 99.9% accurate.