(A) GFP expression of the ΔC-DENV/GFP, ΔCprM/M-DENV/GFP, ΔprM-DENV/GFP, ΔE-DENV/GFP, or the control AcGFP plasmid in BHK-21 cells at 24, 48 and 72 h pt. (B) MFI of GFP in Δ-DENV/GFP transfected BHK-21 cells at 24, 48 and 72 h pt. (C) Western blot analysis of DENV-2 NS1 protein in plasmid-transfected BHK-21 cells on day 7 pt. (a) wt DEN-2 16681 plasmid (pD2/IC-30P-A), and (b) ΔCprM/M-, (c) ΔprM/M-, (d) ΔC-, and (e) ΔE-DENV/GFP plasmids.