Blood separation equipment. Automated apheresis or plasmapheresis machine, used to separate blood while a donor is connected. The blood is separated into its various components, such as plasma, red blood cells and platelets. Only the components that are required are kept, in this case plasma in the bag at lower right. The rest of the blood is returned to the donor. This system allows the blood components that are in short supply to be collected at greater quantities than would be possible from a standard blood donation. Donor blood and its components are given to patients in transfusions, for example during surgery or after accidents.