Site specific integration of FLP recombinase in BHK-21 cell line

A binary system for gene activation and site specific integration based on conditional recombination of transfected sequences mediated by FLP recombinase from yeast was implemented in mammalian cells. In several cell lines, FLP rapidly and precisely recombined copies of its specific target sequences to activate an otherwise silent beta-galactosidase reporter gene. Clones of marked cells were generated by excisional recombination within a chromosomally integrated copy of the silent reporters. These clones exhibited intense blue colour with X-Gal staining solution.