Page "Western blot" Paragraph 42

* The confirmatory HIV test employs a western blot to detect anti-HIV antibody in a human serum sample.

Proteins from known HIV-infected cells are separated and blotted on a membrane as above.

Then, the serum to be tested is applied in the primary antibody incubation step ; free antibody is washed away, and a secondary anti-human antibody linked to an enzyme signal is added.

The stained bands then indicate the proteins to which the patient's serum contains antibody.