A diagnostic or therapeutic formulation of stable liquid coagulation factors comprises at least one coagulation factor, at least one stabilizer, and optional additives. The stabilizer is either amylopectin, galatomannan polysaccharide, agarose, agaropectin, and gelatin, or a blend of amylopectin, galatomannan polysaccharide, agarose, agaropectin, and gelatin. A preferred additive is the zwitterionic buffer 3-[N-tris(hydroxymethyl)methylamino)-2-hydroxypropane sulfonic acid (TAPSO). The stable liquid coagulation factors can be used as reagents and controls in plasma clotting assays. In addition the therapeutic formulation can be used for factor replacement therapy. The stable liquid clotting factors are made by combining the coagulation factor(s), stabilizer(s), and additive(s) in a liquid carrier and sterilizing the mixture. Coagulation factors can be concentrated by selective precipitation from plasma. In addition, the clotting activity of the formulation can be adjusted by adding a factor concentrate to a less concentrated formulation.
