Pelo-TagBFP2 mice are generated via genome editing by knocking in a 3xFLAG tag upstream of the TAA stop codon and an IRES-TagBFP2 cassette ~74 bp downstream of the TAA stop codon in the mouse Pelo gene, enabling TagBFP2 expression driven by endogenous Pelo regulatory elements. TagBFP2 is a fast-maturing, efficiently expressed monomeric blue fluorescent protein with low cytotoxicity, demonstrating robust expression in mammalian cells, bacteria, and other systems. It retains beneficial properties of mTagBFP, including high pH stability and rapid chromophore formation. Enhanced photostability and chromophore chemical stability make it a superior protein tag. This model allows TagBFP2-based fluorescent tracing.