Plasma (55% of whole blood Butty coat leukocytes and platelets (<1% of whole blood formed O Withdraw blood ② Centrifuge Erythrocyte elements and place in tube (45%of whole blood Copynight @2001 Benamin Cummings, an imprint of Addison Wesley Longman, Inc The hematocrit(血细胞比容) is a rapid assessment of blood composition It is the percent of the blood volume that is composed of RBCs (red blood cellsThe hematocrit（血细胞比容） is a rapid assessment of blood composition. It is the percent of the blood volume that is composed of RBCs (red blood cells)