An Expedient Reliable Double Fluorescent Reporter System for φC31 Integrase Function Evaluation

A reporter system for phi C31 integrase was developed in NIH3T3 cells. The reporter plasmid coding green fluorescent Protein (GFP) coupled with red fluorescent protein (R-FP) was co-transfected with the plasmid coding phi C31 integrase, to show the activity of integrase in the cells. Fluorescence activated cell sorter (FACS) was used to measure the proportion of the cells containing red and green fluorescence. The increment of green cells was positively related to the increase in the transfection with plasmid coding phi C31 integrase. Approximately 90% of green cells were observed under a ratio of [plasmid-phi C31-integrase]/[reporter plasmid] at 10 : 1. This suggests that the phi C31 integrase reporter system provides a probe for the function of phi C31 integrase in cells.