A plasma donation appointment runs about one hour and 15 minutes, according to the American Red Cross. During this time, blood is extracted from the donor’s arm and filtered through a machine that will divide the plasma from the blood cells. The red blood cells and platelet components of the blood are then restored to the donor. The plasma is frozen within a 24-hour period and may be preserved for as long as one year. Because plasma from type AB blood can be administered to any patient regardless of their blood type, those with AB blood are encouraged to donate.
However, an individual can make no more than 13 plasma donations in a year. Specifically, appointments must be spaced at least 28 days apart. However, private plasma donation companies may be the exception to the rule. They often allow more routine donations, as frequently as on a weekly basis (via Healthline).