Platelet Concentrate (PC): Platelets prepared from a single unit of whole blood or
plasma and suspended in a specific volume of the original plasma. Also known as
random donor platelets.
Plateletpheresis: A procedure utilizing a machine by which one can selectively
remove platelets from a donor or patient.
Polyclonal: Antibodies derived from more than one antibody-producing parent cell.
Polyspecific Coombs' Sera: A reagent that contains antihuman globulin sera against
IgG immunoglobulin and C3d (complement).
Prophylaxis: Measures taken to prevent disease.
Prozone: Incomplete lattice formation resulting from an excess of antibody molecules
relative to the number of antigen sites. This results in false-negative reactions.
Psoriasis: Chronic inflammatory skin disease characterized by formation of scaly red
QA Unit: One or more individuals designated by, and reporting directly to, top
management with defined authority and responsibility to ensure that all quality
assurance policies are carried out in operations.
Rabies: An acute infectious disease of animals characterized by involvement of the
central nervous system resulting in paralysis and finally death.
RBCs: Red Blood Cells.
Recipient: Refers to a patient who is receiving a transfusion of blood or a blood
Reverse Grouping: Testing a patient's serum with commercial or reagent A and B red
cells to determine which ABO antibodies are present.
Rh Immune Globulin (RhIG): A concentrated, purified anti-D prepared from human
serum, which is given to Rh0 (D)-negative mothers after they have given birth to an Rh0
(D)-positive baby or after abortion or miscarriage. It acts to prevent the mother from
becoming immunized to any D-positive fetal cells that may have entered her circulation
and thereby prevents formation of anti-D by the mother.
Rouleaux: Coinlike stacking of red blood cells in the presence of plasma expanders or
abnormal plasma proteins.
Screening Cells: Group O reagent red cells that are used in antibody detection or