Table 1. Factors for selecting an expression system.

S.No	Factors effecting gene expression
1	Facilities of the laboratory and local expertise.
2	Type of protein to be expressed.
3	Whether the protein is toxic?
4	Whether carbohydrate or other modification required?
5	Reqiurement of large yield of protein.
6	How to purify protein?
7	Production costs.
8	Regulatory considerations.
9	Safety considerations.
10	Purpose for which it is required.