Immunofluorescence localization of CFH within normal platelets. Washed normal human platelets were prepared and imaged as described in Figure 3. CFH labeled with Alexa Fluor 488 (green) is shown in the middle panels; right panels, merged left and middle panels. White bars with the corresponding microns are indicated. (A-D) Representative midplatelet Z-slices. (A) The δ-granule and lysosome protein CD63 does not show specific colocalization with CFH, nor does the lysosomal protein LAMP-1 (B). (C) Partial colocalization of CFH is observed with the platelet surface protein CD61 (β₃ integrin), and (D) strong colocalization is apparent with cytoplasmic actin. Results of whole-cell colocalization analysis are presented in Table 1.