The effects of purified CnPC on the activities of FV and FVIII in canine plasma. Canine plasma pooled from ten dogs and used as a calibrator. For calibration (A and B), the activity level of each coagulation factor in undiluted plasma pool was designated to be 100%; and five 2-fold dilutions yielded activity levels of 50%, 25%, 12.5%, 6.25%, and 3.125%. The activity level of each factor was expressed as a modified APTT, which reflected the abilities of the calibrators to correct the APTT in plasma deficient of a specific coagulation factor. All samples were analyzed in duplicate and the average of the two measurements was used as one true replicate for statistical analysis. Each data point represents the mean (±SEM) of five replicates. The modified APTTs generated in the presence of activated CnPC were compared against a calibration curve generated within the same assay. Percent activity of FV or FVIII was plotted against concentration of the purified canine protein (C and D). Each data point depicted represents the mean (±SEM) of five replicates. The dotted lines delinate the 95% confidence intervals for the curves generated by linear regression.