3. Purification To obtain the viral particles in a single form out of cell debris i.e. removal of all impurities.

4. Purification outline 1.Preparation of harvest. 2.Methods of purification. 3.Criteria of purity. 4.Maintenance of purified virus.

5. Preparation of harvest Bacteria Plant Animal Insect

6. Methods of purification 1.Filtration. 2.Centrifugation. 3.Adsorption. 4.Precipitation. 5.Solvent extraction. 6.Other methods.

7. Methods of purification 1.Filtration. 2.Centrifugation. 3.Adsorption. 4.Precipitation. 5.Solvent extraction. 6.Other methods.

8. : Filtration : 1. Ultrafiltration 2. Gel filtration

9. Ultra-filtration

10. Gel filtration

11. Methods of purification 1.Filtration. 2.Centrifugation. 3.Adsorption. 4.Precipitation. 5.Solvent extraction. 6.Other methods.

12. centrifugation Differential Gradient Isopycnic Cushion

15. Methods of purification 1.Filtration. 2.Centrifugation. 3.Adsorption. 4.Precipitation. 5.Solvent extraction. 6.Other methods.

16. : Adsorption : 1. Ion exchange 2. Heamadsroption

17. Ion exchange chromatography

18. Heamadsorption

19. Methods of purification 1.Filtration. 2.Centrifugation. 3.Adsorption. 4.Precipitation. 5.Solvent extraction. 6.Other methods.

20. : Precipitation : 1. Chemical AmmoniumsufateAmmoniumsufate PEGPEG Zinc acetaeZinc acetae 2. Physical Isoelectric piont (pH change)

21. Methods of purification 1.Filtration. 2.Centrifugation. 3.Adsorption. 4.Precipitation. 5.Solvent extraction. 6.Other methods.

23. Methods of purification 1.Filtration. 2.Centrifugation. 3.Adsorption. 4.Precipitation. 5.Solvent extraction. 6.Other methods.

24. Other methods Electrophoresis. Serological methods. Enzymatic reactions. HPLC

25. Electrophoresis

26. HPLC

27. Criteria of purity Chemical purity Physical purity Biological purity

28. Criteria of purity Spectrophotometer Isoradiation Infectivity serological E.M.

31. Spectrophotometer Isoradiation Infectivity serological E.M.

32. Marking

33. Spectrophotometer Isoradiation Infectivity serological E.M.

34. : Infectivity : 1. Local lesion assay 2. Plaque assay

35. Virus preparation

37. Criteria of purity Spectrophotometer Isoradiation Infectivity serological E.M.

39. Spectrophotometer Isoradiation Infectivity serological E.M.

41. 4- Maintenance: Lyophlization The half life of infectivity can be measured in seconds at 60 oC; minutes at 37 oC, hours at 20oC, days at 4 oC and years at -70 oC or lower, (Fenner et al, 1987)