Dual-intein LVs reconstitute EGFP in vitro. Spontaneous fluorescence in HEK293 cells detected 72 hours post-infection. I: HEK293 cells infected with EGFP LV at (A) MOI 5 and (B) MOI 3; II: HEK293 cells co-infected with the dual-intein EGFP LVs at (A) MOI 2.5 each vector and (B) MOI 1.5 each vector; III: HEK293 cells co-infected with the dual-intein EGFP LVs at (A) MOI 5 each vector and (B) MOI 3 each vector. The image is representative of N = 3 independent experiments.