AU - Vatandoost, Jafar AU - Azimifar, Mohammad amin TI - Expression of Recombinant Factor IX Using the Transient Gene Expression Technique PT - JOURNAL ARTICLE TA - Res-Mol-Med JN - Res-Mol-Med VO - 6 VI - 2 IP - 2 4099 - http://rmm.mazums.ac.ir/article-1-270-en.html 4100 - http://rmm.mazums.ac.ir/article-1-270-en.pdf SO - Res-Mol-Med 2 ABĀ  - Background: Pilot and large-scale production of recombinant proteins require the presence of stable clones, but the process of selecting stable clones is time consuming. Moreover, continuous clone culturing in large-scale production may cause loss of incoming plasmid and recombinant genes. Considering the advancements in Transient Gene Expression (TGE) technology, the large-scale expression of factor IX (FIX) was investigated in HEK cells by the TGE technique. Materials and methods: HEK cells were seeded in a cell factory, and then transfected by pcDNA-hFIX plasmid using calcium phosphate co-precipitation method. Stable HEK-hFIX cells were also seeded in a cell factory, separately. After adding vitamin K, recombinant FIX was quantified in conditioned media using an ELISA. Moreover, its functional activity was assayed using an aPTT test. Results: The results showed that the expression and activity of FIX by TGE technology was, respectively, 1.6 and 1.5 times higher than that obtained through stable HEK-FIX cells. Since calculating the specific activity revealed that for all time periods it is 0.2 mU/ng, so the increase in activity is due to the increase in the amount of FIX. Conclusions: HEK cells with higher transfectability seemed to be an appropriate alternative for transient expression for large-scale protein production. Furthermore, if rapid expression of recombinant proteins is intended, TGE can replace costly and low-yield methods. CP - IRAN IN - Sabzevar LG - eng PB - Res-Mol-Med PG - 29 PT - Research YR - 2018