Blocking experiments of CD300a-Ig binding to dead cells and liposomes. Starved PBMCs from healthy donors were preincubated with increasing concentrations of MFG-E8 (A) and duramycin (B). Then, the binding of Alexa Fluor 488 (AF488) CD300a-Ig to the 7-AAD positive cells was assessed and the percentage change in CD300-Ig binding as a function of different concentrations of MFG-E8 (A) and duramycin (B) is shown. Each bar graph is a representative example of 2 independent experiments. Blocking of CD300a-Ig binding to PS and PE containing liposomes by annexin V (C) and duramycin (D) is shown. The detailed procedure is described in supplemental Methods. The y-axis indicates the strength of binding by proteins to the immobilized liposomes on the L1 chip. The 1-headed arrows correspond to the reagents added as specified in the graph. The double-headed arrows indicate the binding ability of the proteins specified as RU. Note that the data points for the complete dissociation curve after the injection of NaCl plus EDTA have been removed. The data are a representative of 2 independent experiments.