Soluble expression of recombinant coagulation factor IX protein using Escherichia coli

Hemophilia B is a congenital bleeding disorder caused by factor IX (FIX) deficiency. Generation of recombinant FIX (rFIX) is required for detecting a Hemophilia B indicator, anti-FIX antibody. In this study, we described a method for producing recombinant FIX (rFIX) using Escherichia coli. We constructed a FIX-expressing plasmid without a fusion tag protein-encoding gene and produced rFIX as a soluble form within five days. Dose-dependent curve was obtained from ELISA using anti-FIX antibody, indicating that the rFIX can be used as an antigen to detect anti-FIX antibody with high affinity and sensitivity.