title: Effect of freeze-drying, freezing and frozen storage of blood plasma on fibrin network characteristics.
abstract: BACKGROUND
  We investigated the effect of freezing, freeze-drying and the duration of frozen storage of blood plasma on fibrin network characteristics of clots subsequently produced.
  
  
  METHODS
  Fibrin network characteristics of clots made from freeze-dried and frozen plasma were compared to those made from fresh plasma. Freeze-dried pooled plasma was reconstituted and frozen each month for 4 months to describe the differences in fibrin networks that occur as a result of storage of the plasma over this period.
  
  
  RESULTS
  Compared to freezing, freeze-drying of plasma had fewer undesirable effects on the fibrin network characteristics measured. Only the permeability of the clots from freeze-dried plasma was significantly less compared to the values of clots from the fresh plasma (p=0.005). Fibrinogen activity and mass-length ratio, compaction and fibrin content of the clots made from frozen plasma were, however, all significantly affected by freezing. Mass-length ratio and compaction showed a linear decrease and fibrin content a linear increase over a 4-month frozen storage period, thereby indicating that these variables were probably not stable. Large variation found in the data from each month indicates that there may be other factors, apart from storage time, that have a larger influence on these fibrin network characteristics, than frozen storage of plasma for 4 months. Storage of plasma in the freeze-dried form for 4 months resulted in a significant increase in fibrinogen (p=0.0004) but significant decrease in fibrin content (p=0.0002).
  
  
  CONCLUSIONS
  Although the process of freeze-drying had fewer undesirable effects on the measured fibrin network characteristics compared to freezing, storage in both forms resulted in altered activity upon rehydration and thawing.
authors.affiliation: Potchefstroom Institute of Nutrition, Potchefstroom University for Christian Higher Education, Private Bag X6001, Potchefstroom 2520, South Africa. M.Pieters@pg.tno.nl
authors.forename: Marlien
authors.initials: M
authors.lastname: Pieters
authors.forename: Johann C
authors.initials: JC
authors.lastname: Jerling
authors.forename: John W
authors.initials: JW
authors.lastname: Weisel
mesh_terms: D001777:Blood Coagulation; D001793:Blood Preservation / Q000379:methods* / Q000592:standards*; D015925:Cryopreservation / Q000379:methods / Q000592:standards; D005337:Fibrin / Q000737:chemistry / Q000648:ultrastructure*; D005612:Freeze Drying; D006801:Humans; D010539:Permeability; D011487:Protein Conformation
chemical_list: D005337:Fibrin