FIG. 4.

Immunoblot confirmation of specific antibody responses to native sBARF1. Native sBARF1 was loaded on a reduced SDS-PAGE gel, blotted to nitrocellulose, and cut into strips. Sera from the highest responders in the NPC patient panel and control sera were analyzed at 1:100 dilution. 4A6 anti-BARF1 antibody was used as a positive control (C). A band at the correct height was detected with most of the selected NPC patient sera only upon considerable overexposure (minutes) when using ECL visualization. The 4A6 signal was revealed in a few seconds.