FIG. 6.

Gradient purification and characterization of KSHV virions for binding and infection studies. Infectious KSHV virions were purified from culture medium of TPA-induced BCBL cells by double-step gradient centrifugation in Opti-Prep. (A) Virus-containing fractions were identified by real-time quantitative PCR analysis for KSHV genomic DNA. (B, C) Biotinylated virions showed discrete staining and colocalization (arrows) of antibody reactivity to biotin (B) and KSHV envelope-associated glycoprotein K8.1 (C). Bar, 5 μm.