Tehran University of Medical Sciences Journal of Medical Bacteriology 2251-8649 3 3-4 2015 10 13 8 13 EN Ehsan Zayerzadeh Department of Biology, Faculty of Food Industry and Agriculture, Standard Research Institute, Karaj, IR Iran. Azadeh Fardipour Department of Vaccine Quality Control, Razi Vaccine and Serum Research Institute, Karaj, IR Iran. Ahmad Reza Jabbari Department of Anaerobic Bacterial Vaccine Research & Production, Razi Vaccine and Serum Research Institute, Karaj, IR Iran. 2015 10 12 2015 10 12 Background: Clostridium perfringens type C strains cause severe necrotizing enteritis in sheep, calves, goats, pigs and humans. Beta-toxin is introduced to be the essential virulence factor of this microorganism. In the present study, a new method was established for the purification of beta toxin from culture supernatant fluid of C. perfringens type C vaccinal strain. Methods: The four steps of the purification scheme involved ammonium sulfate precipitation, cation exchange chromatography (CM- Sepharose), anoion exchange chromatography (DEAECellulose) and gel filtration (Sephadex G-100). Results: Beta toxin was purified about 78-fold from the Sephadex G-100 column with a yield of about 16.7% in terms of lethality of the toxin. The molecular weight of the beta toxin as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was approximately 37 KD. The LD50 for adult mice was 2.21 μg/kg. Human umbilical vein endothelial cells (HUVEC) exposed to CPB showed a cell border retraction, cytoplasmic blebbing, cell shrinkage and cell rounding. The toxin was heat labile and was inactivated by trypsin. Conclusions: In conclusion, the results of this study showed the new protocol is suitable for purification of beta toxin of C. perfringens type C regarding good purity, good yields and high activity of beta toxin. https://jmb.tums.ac.ir/index.php/jmb/article/view/25 https://jmb.tums.ac.ir/index.php/jmb/article/download/25/20