4 267 269 a conventional in line frangible cannula 24 and in line clamps 25 control fluid flow through the tubing 30 18 among the bags 16 18 and 26 all of the bags 16 18 and 26 and tubing 30 associated with the processing assembly 12 can be made from conventional approved medical grade plastic materials such as polyvinyl chloride plasticized with di 2 ethylhexylphthalate dehp the blood collection assembly 12 once sterilized constitutes a sterile u201c closed u201d system as judged by the applicable standards in the united states preferably as fig2 shows before whole blood is collected a removable donor specific label 25 is attached to the primary blood bag 16 the label 25 carries a unique identification number assigned to the particular donor at the time of donation whole blood is collected from the donor in the primary bag 16 the whole blood is separated by centrifugation in the primary bag 16 into red blood cells and platelet rich plasma in the process of centrifugally separating these components a layer rich in leukocytes forms between the red blood cells and the platelet rich plasma the platelet rich plasma is transferred by conventional techniques into the transfer bag 18 leaving the red blood cells designated rbc and leukocytes designated lc in the primary bag 16 the red cell storage solution s is then transferred from the bag 26 to the primary bag 16 through the transfer tubing 30 as fig3 shows the.