Glossary of Terms

  • Plasma: The liquid portion of whole blood when it is collected with an anti-coagulant. The whole blood is separated by centrifugation, and the blood cells are removed from the liquid portion. This contains all of the blood proteins including the clotting factors.
  • Recovered Plasma: The plasma collected (separated) from a single donor bleed. The volumes are usually less than 300 ml / bleed.
  • Source Plasma: The plasma collected from donors that are aphoresised. Aphoreises is the process of taking whole blood out and separating the cellular portion from the liquid portion and returning the cellular portion back with fluid. A donor can be aphoresed up to twice a week depending on disease process. The volumes are usually greater than 600 ml and less than 880 ml depending on the size and weight of the donor.
  • Anticoagulant: A chemical that inhibits the clotting process of blood components. This material is added to the collection bag / container. Common anticoagulants are Sodium citrate, Acid Citrate Dextrose (ACD), CDP, CDP-A, EDTA and Na Heparin.
  • Serum (Off Clot Serum): The liquid portion of blood when collected without anticoagulant. The unit is allowed to clot, and the liquid portion is separated from the clotted blood cells. This contains all of the blood protein excluding the clotting factors.
  • Control: The term “Control” means different things to different people. Plasma Services Group defines “Control” as any plasma or serum based material to which the potency has been adjusted in some manner and is not neat out of the donor.
  • Defibrinated Plasma: This is essentially similar to serum as defined above except that the clotting process is done in the laboratory. Defibrination can be achieved by physical (diafiltration) or chemical means. The most popular processes involve using Calcium chloride in conjunction with (bovine) thrombin. In most cases, the Calcium chloride has to be removed as it may interfere with some assays. Bovine Thrombin can be used without added Calcium chloride.
  • Delipidization: This is the physical or chemical reduction or elimination of lipids to clarify the serum or plasma. Some IVD products require that the defibrinated plasma or serum be optically clear. Chloroform or Freon (1,1,2 trichlor-tri flour ethane) is most commonly used. Other methods include using fumed silica at 1 % W/V or Dextran sulfate depending on the intended use of the final product.
  • Titer: This is the potency or the measurement of the amount of analyte in a specimen. This can be reported in several different ways. International Units (IU) may be used when there is a recognized reference standard available. (Check the WHO or the CDC website for available reference standards.) Relative Units (RU) may be utilized when no reference standard is available. And, finally, titer may also be expressed as a concentration such as weighted amount/ volume (i.e. mg/ml).