Photograph of electrophoretically separated cell lysates reacted with polyclonal rabbit antibody to a GST-US3 fusion protein. Replicate 25-cm2 flask cultures of HEp-2 cells were mock infected or infected for 24 h at 37°C with 10 PFU of HSV-1(F) or R7041 per cell, harvested, solubilized, electrophoretically separated on denaturing gels, electrically transferred to a nitrocellulose sheet, and reacted with rabbit antibody to a GST-US3 fusion protein.