Blood collected from the donor is not immediately available for transfusion. The blood must be tested and processed. Processed to separate the plasma (which contains white blood cells) from the liquid, red blood cell filled portion. The donor does not wait around for this testing and processing to take place. Here’s what happens immediately following their donation: 1) Two test tubes of blood are filled from the donor’s sample bag and sent to the lab.

2) Blood in the collection bag is hung on a rack at a specific height and filtered through a white blood cell filter and an air lock filter.

3) The filtered blood bag is placed in a centrifuge to separate the plasma (solid portion) from the liquid (red blood cell filled) portion.

4) The blood bag is then pressed and the plasma removed.

5) The plasma is frozen. It is good for one year.

6) A special nutrient is added to the fluid, red blood cell portion, to keep the red blood cells alive for 42 days.

7) This blood bag is placed in the quarantine fridge. It cannot be used for transfusion as the lab results will still be needed at this point.

8) Test results return between 12 and 24 hours.

9) When the tests have cleared a unit of blood, it can be moved out of quarantine. Such blood is transferred down the hall to the blood bank where it is available for transfusion.