Figure 2: Top, Annexin V assay to quantify the amount of PS exposed on the outer cell membrane.

Bottom, cholesterol content assay, quantifying the total cellular cholesterol. The error bars are relative to the standard deviation of three repeated experiments. The quantification of the cellular levels of PS in living cells was performed by flow cytometry using Alexa Fluor® 488 Annexin V Kit (Molecular Probes). Total cellular cholesterol was quantified by reverse phase HPLC on cellular homogenates previously treated with cholesterol oxidase and cholesterol esterase.