HIV p24 measured in supernatant. Microglia were exposed for 4 hr to stock HIVBaL virus (equivalent to 5,000 pg/mL of p24), then washed in PBS. Aliquots of extracellular supernatant were then removed immediately (day 1 on plot) and after 9 d in culture, then p24 measured by ELISA. Plotted are means of three biological replicates with standard deviation. ND — not detected. P24 was was significantly higher in HIV + than HIV + RAL at 9 d (P < 0.001), and HIV + RAL was not significantly different from uninfected at 9 d (P = 0.19), by ANOVA and Tukey Honestly Significant Difference test.