A histogram of fluorescent events vs. fluorescent intensity for HL-60 cells. Left: control cells with no fluorescent probe added. Center: cells that have been incubated with the fluorescent probe in the presence of 10% P105 micelles for one hour. Right: cells that have been incubated with the fluorescent probe in a solution of PBS for one hour. Using Lysosensor Green and flow cytometry, more fluorescence is observed when the probe is introduced in a solution of PBS than when encapsulated in P105.