An improved molecular tool for screening bacterial colonies using GFP expression enhanced by a Dictyostelium sequence.

During molecular cloning, screening bacterial transformants is a time-consuming and labor-intensive process; however, tractable tools that can be applied to various vectors for visual confirmation of desired colonies are limited. Recently, we reported that translational enhancement by a Dictyostelium gene sequence (TED) boosted protein expression even without an expression inducer in Escherichia coli. Here, we demonstrate a generally applicable molecular tool using the expression of green fluorescent protein enhanced by TED. By inserting a module related to TED into the cloning site in advance, we effectively screened E. coli colonies harboring the desired plasmid functions in a prokaryote (Magnetospirillum gryphiswaldense) or eukaryote (Dictyostelium discoideum). Thus, our system represents a user-friendly technique for cloning.