Fluorescent “Turn-on” system utilizing a quencher-conjugated peptide for specific protein labeling of living cells

► The newly synthesized compounds worked for labeling hexahistidine-tag in living cells. ► The labeling is performed without washing, because the signals appear, only when the compounds bind to the targets. ► This method would be a powerful tool as a labeling method for cytoplasm (inside cells) and in vivo.