Abstract:ObjectiveTo assay the coagulation factor IX -knockout mice. MethodsThe DNA of mice was analysed by PCR and the plasma of the mice was measured by one stage method. ResultsPCR analysis of FIX mice was positive and FIX activity was below 5%. ConclusionThe result showed that the coagulation FIX -knockout mice could be generated steadily and exhibited a phenotype similar to human hemophilia B.