Variation of platelet CD36 surface expression in a normal population. PRP from human subjects was incubated with either PE-conjugated anti-CD36 IgG or its isotype control and then analyzed by flow cytometry. (A) Left panel: representative histogram from a subject expressing high CD36 levels. Middle panel: Representative histogram from a subject expressing low CD36 levels. Right panel: histogram from a CD36 null subject. (B) CD36 expression levels on platelets from 32 normal volunteer donors were quantified as described in the “Quantitative assay of platelet CD36 expression.” Each triangle represents a single donor at one point in time. (C) Four donors were analyzed at least 5 times over time periods of 3 to 6 months. Bar graph represents the mean and coefficient of variance of platelet CD36 expression.