title: Lyophilised plasmas for one-stage determination of factor VIII.
abstract: Two batches of lyophilized normal pooled HEPES-stabilized plasma according to ZUCKER [11] and LOELIGER [7] were prepared. The F VIII activity established by the activated partial thromboplastin test (APTT-VIII) was identical in both plasmas and amounted to 0.99 U/ml (95% confidence limits 0.87 to 1.17 U/ml). It did not change within 11 months in plasmas according to ZUCKER, and 6 months in those according to LOELIGER (further on not followed). We prepared four batches of lyophilized HERPES-stabilized substrate plasma (severe form of hemophilia A) according to ZUCKER. They were employed for 5 to 13 months in APTT-VIII along with the frozen 3.2% sodium citrate substrate plasmas. The results showed a satisfactory agreement. The lyophilized plasmas did not influence even the dose-response-line. On the ground of these results we consider the reported lyophilized plasmas to be suitable reagents in APTT-VIII technique.
mesh_terms: D001780:Blood Coagulation Tests / Q000592:standards*; D001793:Blood Preservation; D005169:Factor VIII / Q000032:analysis*; D005612:Freeze Drying; D006467:Hemophilia A / Q000097:blood; D006801:Humans; D010314:Partial Thromboplastin Time / Q000592:standards*; D010949:Plasma
chemical_list: D005169:Factor VIII