SUA-rIgG competition of ALSV-A Env mediated infection. Cells transduced with Tva800 vectors were challenged with 10 μl ASLV-A Env pseudotyped NB-MLV mixed with 0-500 μl of SUA-rIgG-containing supernatant,. Infection was assessed by two-colour FACS as described above. (A) Tva800AGG, MOI 0.14, 1.4 and 11. (B) Tva800ATG, MOI 0.16, 1.6, and 8. Representative results from three (A) and four (B) experiments performed are shown.