Effect of oligonucleotides on intrinsic tenase complex activity. Increasing concentrations of oligonucleotide were added to an intrinsic tenase reaction containing final concentrations of 84 pmol/L human factor VIIIa, 3 nmol/L human factor IXa_B, 2% (vol/vol) rabbit brain cephalin, in 0.15 mol/L NaCl, 20 mmol/L HEPES, pH 7.4, 2 mmol/L CaCl₂, and 0.1% PEG-8000 buffer. Human factor X was added to 300 nmol/L and the reaction sampled (50 μL) at 15, 30, 45, and 60 seconds into 10 μL of 0.25 mol/L EDTA, pH 8.0. The chromogenic substrate S-2765 was then added to 300 μmol/L with polybrene 70 μg/mL and the amount of factor Xa generated determined by comparison of the rate of cleavage with a standard curve (see Materials and Methods). The dose response for ISIS 2302 (antisense) (•), sense (○), scrambled (▪), and phosphodiester oligonucleotides (□) is shown. The rate of factor Xa generation (nmol/L/min) in the presence of oligonucleotide was expressed as a percentage of the control value without oligonucleotide present. Data points represent the average of two determinations.