abstract |
The present invention relates to expression cassettes libraries of expression vectors comprising the same, wherein each vector comprises at least one gene of interest and a promoter operatively linked thereto wherein each promoter comprises a nucleic acid, whose sequence is randomly mutated with respect to that of another in the library and cells comprising the same. Methods utilizing either the libraries or cells of this invention, in optimizing gene expression, protein expression, or optimized gene or protein delivery are described. |