Enzymatically Incorporated Genomic Tags for Optical Mapping of DNA‐Binding Proteins

All smiles: Sequence-specific methyltransferase-induced labeling of DNA (SMILing DNA) creates a fluorescence pattern of the T7 bacteriophage genome (see picture). The pattern is visualized as a linear optical barcode showing the genomic location of individual RNA polymerases bound to the DNA. The precision of the measurement presents new opportunities for contextual genomic research on the single-molecule level.