The present invention provides a composition, comprising: proaccelerin (factor V) and at least one factor selected from the group consisting of: prothrombin (factor II), proconvertin (factor VII), and Stuart-Prower factor (factor X), wherein an amount of the proaccelerin in the composition is between 75% to 750% compared to an amount of proaccelerin in a blood plasma, and wherein an amount of the at least one factor is from 150% to 3000% compared to an amount of the at least one factor in the blood plasma； wherein the amount of proaccelerin and the at least one factor in the composition is determined by extrapolating an observed activity of the composition at a concentration of 500 mM NaCl, using a prothrombin complementation assay using a standard curve constructed using the blood plasma.
