(a) IP6, dNTP, both or neither were added to capsid cores at the indicated time points and ERT measured at 48 hr in the absence of nuclease. IP6 added at 0 hr maintains HIV capsid integrity sufficiently to allow ERT when dNTPs are added 24rs later. Data are plotted as the mean ± SD of three replicates. (b) Schematic of the core opening assay. (c) Field-of-view of GFP +intact capsids at different time points and concentrations of IP6 (d) Example traces of single particle GFP release upon core opening. Traces from four individual virions undergoing core opening at different times are shown for each condition. (e) Fraction of intact cores as a function of time (f) Half-life of core opening.