Circulating CD41⁺ platelets and GpA⁺ erythrocytes in the PB of CD34⁺transplanted SCID mice. Blood was collected in the presence of 2 g/L EDTA and stained immediately with CD41-FITC (B) and GpA-FITC (C). (A) shows the blood of a nontransplanted mouse stained with CD41-FITC.