The purpose of the present investigation was to comparatively evaluate the performance characteristics of the test systems designed to verify the positive results of screening survey for HIV infection, such as the solid-phase immunoassay DS-EIA-HIV-AB/AG-SPECTR (Diagnosticheskiye Sistemy (Diagnostic Systems) Research-and-Production Association, Nizhni Novgorod) and tests based on immune blotting (IB). The investigation examined 15 seroconversion panels produced by ZeptoMetrix (USA) and BBI (USA). The use of the DS-EIA-HIV-AB/AG-SPECTR test system determined 88 of the 167 seroconversion panels as HIV positive. The IB-based tests revealed only 45 of the 167 samples as positive. Consequently, the application of the DS-EIA-HIV-AB/AG-SPECTR test system is more effective than the IB-based tests in early HIV infection.