FIG 1.

Selection of resistance to EFdA by serial passage. Time to breakthrough was determined (in MT-2 cells) as the number of days required for ≥75% syncytium formation, at which point the supernatants were harvested, assayed for p24 content, and used to infect the subsequent passage. EFdA concentration was doubled every second passage until P₆ and then every passage thereafter. Results represent a single trial for each passage. Passages were initiated with WT (xxLAI) (A), K65R (B), M184V (C), and D67N/K70R/T215F/K219Q (D).