IEM of cytoplasmic vesicles in Nef-expressing CEM-SS cells using endosomal and lysosomal markers. EM was performed on cryosections of CEM-SS cells expressing HIV-1NL43 Nef stained with no primary reagent (A), anti-cathepsin D (B), or anti-LAMP 2 (C), followed by secondary 10-nm colloidal gold conjugates. CEM-SS cells expressing HIV-1cons Nef were stained with anti-CI-M6PR followed by 10-nm colloidal gold conjugates (D). G, Golgi complex; N, nucleus.