Figure 2. The relative fluorescence intensity of EGFP measured by 96-well plate reader EGFP represents the relatively fluorescence intensity of BL21(DE3) transformed with plasmid encoding EGFP protein. The Negative represents the relatively fluorescence intensity of BL21(DE3) transformed with plasmid encoding nonsense mutated EGFP protein. Significant difference between them shows that EGFP can be expressed and function well inside E.coli cells.