During pre-operative investigations, a man found to have positive serological results for HIV. Which of the following is highly specific test for HIV antibodies in this patient?

The Western blot test is used as a measure of specific HIV-1 antibodies to confirm a positive ELISA result. The criterion for a positive test is any two bands corresponding to p24, gp41, and gp120/160. The absence of bands is a negative result, whereas the presence of bands that do not meet the criterion for a positive test is an indeterminate result. False-positive and false-negative results are relatively uncommon. HIV-2-infected patients may give an unusual pattern on an HIV-1 Western blot; therefore, if HIV-2 is suspected, a separate HIV-2 Western blot is required. Ref: Brooks G.F., Carroll K.C., Butel J.S., Morse S.A., Mietzner T.A. (2013). Chapter 47. Principles of Diagnostic Medical Microbiology. In G.F. Brooks, K.C. Carroll, J.S. Butel, S.A. Morse, T.A. Mietzner (Eds), Jawetz, Melnick, & Adelberg's Medical Microbiology, 26e.