FIG. 7.

Separation of retroviral particles with a MAb specific for an insert in SU. Mixtures of wild-type and V1/V2_CaseA2 273/274 chimeric viruses were subjected to negative enrichment with MAb SC258 at 5 μg/ml on Pansorbin (A) or positive enrichment with SC258 at the indicated concentrations and His₆-protein (A) on Ni²⁺-NTA resin (B). Virus mixtures before and after enrichment were expanded in 3T3 cells, and [³⁵S]cysteine-labeled culture supernatants were analyzed by RIP with hyperimmune anti-gp70 serum, followed by SDS-PAGE and autoradiography. S, starting mixture; FT, virus not removed by Pansorbin; E20, virus eluted from Ni²⁺-NTA when SC258 was used at 20 μg/ml; E5, virus eluted from Ni²⁺-NTA when SC258 was used at 5 μg/ml; E1, virus eluted from Ni²⁺-NTA when SC258 was used at 1 μg/ml.