Production of an Efficient Enzymatically Fab Fragment Antivenom against Cobra Snake (Naja naja oxiana) Venom.

Since around 100 years ago, the best treatment for millions of global snakebite victims has been polyclonal antivenoms. However, common antivenoms need continuous improvement to reduce rare, their side effects and get better performance. In the present study, Fab antivenom was produced through papain digestion of anti-cobra venom plasma, multi-step purification, and optimization, including ammonium sulfate precipitation and DEAE-cellulose column chromatography. Then, the existence of the corresponding Fab fragment antibody was seen and confirmed by SDS-PAGE method and double immunodifusion (Ouchterlony) test. In addition, the potency test in NIH laboratory mice revealed that each milliliter of the new Fab antivenom was able to neutralize 624 micrograms and (80LD₅₀) of cobra venom, which is about 15% more efficient than the primary plasma of the same concentration, and 1.57 times more effective than the cobra antivenom found in commercial hexavalent antivenom of Razi Institute. According to the findings, it seems that this new Fab antivenom can be used as a new candidate for treatment of cobra snakebite victims.