Figure 3.
Sensitivity to detect CXCR4-using variants within mixed viral populations. The results are the geometric mean RLU from multiple replicates with SE error bars. Minor species of X4-tropic env from HXB2 was detected consistently at 1% and approximately 50% of the times at 0.5%. Use of CXCR4 for entry was confirmed by ablation of the luciferase signal with the addition of AMD3100, which decreased the RLU to minimal levels. Luciferase activity in U87-CXCR4 cells decreased proportionally to the proportion of input DNA from X4 virus.