Platelets are blood cells that help control bleeding. When a blood vessel is damaged, platelets collect at the site of the injury and temporarily repair the tear.
Platelets then activate substances in plasma which form a clot and allow the wound to heal.
During the apheresis procedure, all but the needed blood component is returned to the donor. Different patients need different types of blood components, depending on their illness or injury. After you donate whole blood, the unit is separated into platelets , red cells and plasma in our laboratory. Only two tablespoons of platelets are collected from a whole blood donation. Six whole blood donations must be separated and pooled to provide a single platelet transfusion.