Stability of von Willebrand factor and factor VIII in canine cryoprecipitate under various conditions of storage

The stability of factor VIII and von Willebrand factor antigen in canine cryoprecipitate obtained from seven greyhound donors was determined after storage under various conditions, including twice freezing at −70°C and thawing at 37°C, slow thawing at 4°C, refreezing the slowly thawed cryoprecipitate at −20°C and thawing at 37°C and maintaining the thawed cryoprecipitate at room temperature for 24 hours. The results indicated that factor VIII and von Willebrand factor antigen were effectively concentrated during the initial cryoprecipitation procedure. The cryoprecipitate which had been thawed and refrozen under the above conditions maintained factor VIII activities and concentrations of von Willebrand factor antigen similar to those in the original thawed cryoprecipitate. Furthermore, there was no significant loss of either of the coagulation factors in cryoprecipitate which was thawed in a warm water bath and stored for 24 hours at room temperature.