A novel reporter system for bacterial and mammalian cells based on the non-ribosomal peptide indigoidine

► Engineered mammalian cells produce the non-ribosomal peptide indigoidine. ► Indigoidine is an inert blue pigment that can be extracted and quantified in a single step. ► The colorless fluorescent leuco-indigoidine is compatible with FACS analysis. ► Indigoidine is a versatile and universal reporter for bacteria and mammalian cells.