Percoll density-gradient centrifugation of blood. (A) MHOAH, (B) M-Tg98Ru, (C) M-Tg58Ru, and (D) Tg58 × Tg98. Blood from M-Tg58Ru and Tg58 × Tg98 mice contained 13% to 15% reticulocytes that sedimented largely to the interface of PBS and the 1.094 specific gravity Percoll. Blood from each line of transgenic sickle cell mice had denser than normal RBCs that sedimented to the interface of the 1.107 and 1.111 specific gravity Percoll.