Analysis of HML-2 Gag protein expression in Tera-1 cells and pRVLP. (A) Immunocytochemistry was performed on fixed and permeabilized Tera-1 cells, using an HML-2 Gag-specific polyclonal rabbit serum (Anti-serum) or the corresponding preimmune serum (Pre-serum) as a control. Nuclei were stained with DAPI. Arrows indicate immunoreactivity for HML-2 Gag. Magnification, ×1,000. (B) Immunoblot analysis of HML-2 Gag protein in Tera-1 cells and pRVLP. The blot was probed with anti-HML-2 Gag polyclonal rabbit serum. Tera-1 cells, protein lysate of Tera-1 cells; IP Pre-serum, protein lysate of Tera-1 cells immunoprecipitated with HML-2 Gag preimmune serum; IP Anti-serum, protein lysate of Tera-1 cells immunoprecipitated with anti-HML-2 Gag antiserum; Tera-1 pRVLP, protein lysate of the pellet from an ultracentrifuged supernatant of Tera-1 cells. Filled arrow, position of HML-2 Gag precursor protein; open arrows, positions of processed HML-2 Gag proteins; HC and LC, positions of immunoglobulin heavy and light chains in the IP lanes.