Figure 1. QuantiBRITE beads are used to quantify the relationship between PE fluorescence and number of PE molecules attached to a bead/cell.
A) QuantiBRITE beads are analyzed by flow cytometry to calculate the mean, log PE fluorescence of the four bead populations, each conjugated to a different, known number of PE molecules. B) The relationship between log (PE molecules/bead) and log (log PE) is then determined. This relationship can then be used to translate the mean PE fluorescence of stained cells into the mean number of CD4 or CCR5 antibody binding sites (ABS) per cell.