Evaluation of Preanalytical Variables Associated with Measurement of Prothrombin Fragment 1.2

We have used a monoclonal antibody-based ELISA for plasma prothrombin fragment 1.2 (Fl.2) to establish ap-propriate sample collection and storage conditionsfor this biomarker of thrombin generation. Fl.2 concentrations were not altered by exogenous factor Xa, thrombin, or thromboplastin if blood was collected by routinevenipunc-ture into tubes containing heparin as anticoagulant (but not citrate, acid-citrate-dextrose, EDTA, or oxalate) and if plasma antithrombin Ill concentration was 30 % of nor-mal. Heparinized plasma Fl.2 was stable for 8 h at 20-25#{176}C,and if premixed with a stabilizing reagent, for 4 years at-70#{176}C.Mean values for heparinized plasma Fl.2 collected and stored by recommended procedures were increased in patients with thrombosisand conditions of increased thrombotic risk, and were sensitive to hepa