Actin fs activated ptt reagent

DNA aptamer RA-36, dGGTTGGTGTGGTTGGTGGTTGGTGTGGTTGG⋅2 KCl, was synthesized and purified up to pharmaceutical grade for intravenous injections at ‘APTO-PHARM,’ Ltd. Russian Federation. The drug formulation for intravenous injections contained 10 mg/ml of the active substance in 0.9% sodium chloride solution; to prepare that formulation, the aptamer stock solution was diluted with 0.9% sodium chloride immediately before the intravenous injection, when proper dosing is needed.
Lyophilized bivalirudin (Angiox^®, lot# PL2097) was purchased from Medicines Company, United Kingdom. The powder was dissolved in 0.9% sodium chloride at a concentration of 5 mg/ml according to the manufacturer’s guidelines. The stock solution was diluted with 0.9% sodium chloride immediately before intravenous injection, when proper dosing is needed.
Standard human plasma, Test Thrombin Reagent, Thromborel^® S and Actin FS Activated PTT Reagent were purchased from Siemens, Germany. ³²P-labeled ATP with beta radiation activity of 20 MBq was purchased from Perkin-Elmer, United States. T4 polynucleotide kinase (Sigma–Aldrich, United States).

Samples of citrated blood were centrifuged for 15 min at 1400 rpm to separate plasma from blood cells. Coagulation of blood plasma was estimated with coagulometer CA-50 (Sysmex, Japan) using the reagent sets from Siemens, Germany: Test Thrombin Reagent for thrombin time (TT) determination, Thromborel^® S for prothrombin time (PT) determination, Actin FS Activated PTT Reagent for activated partial thromboplastin time (APTT) determination. Standard Human Plasma was used to test the functional activity of the reagents. Aptamer RA-36 and bivalirudin prolong coagulation time of blood plasma due to thrombin inhibiting. The data were treated with Origin 8.1 (OriginLab, United States). Descriptive statistics was performed, including mean values, geometrical mean values, standard deviations, coefficients of variation, medians, lower 90% CI of mean and upper 90% CI of mean.