Immunolabeling of GPS MKs.

(A) vWF immunolabeling is found in small granules (g) often located near the Golgi complex and in the lumen of the demarcation membrane system (dms). Multivesicular bodies (MvB) are consistently negative (original magnification × 37 000; inset, × 46 000). (B) P-selectin is detected within multivesicular bodies (MvB) and in some vacuolar structures (A′) the size of normal α-granules. The demarcation membrane system (dms) is free of labeling (original magnification × 37 000; inset, × 2000).