Production of functional recombinant human tissue factor for the prothrombin time test

Tissue factor (TF) triggers extrinsic blood coagulation and is used for the prothrombin time test to investigate blood disorders.TF consists of the N-terminal extracellular, the transmembrane, and the C-terminal cytoplasmic domains.Here, a convenient method for preparing active recombinant TF for the prothrombin time test is described.The sole extracellular domain (TF219) and the transmembrane domain which is linked to TF219 (TF243) were produced in Escherichia coli.The recombinant TF243 was retained on the 300 kDa molecular weight cut-off filter membrane, though TF219 passed through it.The retained TF243 increased the stability to be stable at room temperature for a week probably due to removing contaminants, whereas TF243 in crude extract was inactivated after the incubation for three days at the same conditions.