a, b12 titration curve showing the proportion of COS-7 cells expressing Gag-iCherry 24 h after HIVHXB2-Gag-iCherry exposure incubated with different concentrations of the antibody; the squares represent the average values, and the error bars denote the s.d. for n = 10 cells. b, Time-resolved oligomeric states for CXCR4-mTFP1 (green dots) and CD4-mOrange (red dots) following exposure to HIVHXB2-Gag-iCherry virions in the presence of 100 μg/mL b12. These virions did not induce positive Bcc. The circles represent the average values, and the whiskers denote the standard error for n = 12 events.