Human plasma is commonly used in manufacturing processes that involve primary human cells or cell lines intended for
therapeutic applications. In these applications, plasma provides a source of protein and possibly other factors that enhance
expansion and differentiation of cell populations. A variety of methods have been used to prepare human plasma and derivatives
for ancillary use, but the practices are not standardized. Allogeneic plasma typically is obtained from either apheresis or whole
blood, using citrate anticoagulation. Allogeneic plasma typically is collected from paid donors who, like Source Plasma donors,
have been screened for the absence of transfusion-transmissible diseases. Preferred donors may be blood type group AB, because
they lack anti-A and anti-B isohemagglutinins. Other preferred donors include untransfused males, because this group is unlikely
to have human leukocyte antigen (HLA) antibodies that could react with cells in a given culture system. Serum is prepared either
from nonanticoagulated whole blood that has been allowed to clot or by the addition of calcium to plasma obtained from
citrated whole blood or apheresis. Heating plasma or serum to 56° inactivates heat-labile complement and other proteins.
Although there are no standardized specifications for plasma products used as ancillary materials, assays often include safety
testing associated with general biologics (e.g., bacterial/fungal cultures, endotoxin, and mycoplasma). In addition,
characterization of the products may include tests for irregular erythrocyte and HLA antibodies, osmolality, pH, total protein
and immunoglobulin concentrations, hemoglobin concentration, and chemistries such as Na, K, Cl, Ca, and glucose.
