Transformed from Mouse CT26 cell line, the firefly Luciferase3 and RFP was constitutively co-expressed under the enhanced EF1a promoter as two separated proteins(not as fusion), mediated via F2A element. The Puromycin resistance marker was expressed under Rsv promoter. Each cell demonstrates strong RFP fluorescent signal and luciferase assay signal via Luc assay(Note: It is the pooled polyclonal population, not originated from a single cell colony. Thus you will observe the uneven RFP signal intensity amount cells).