NADA-green is a fluorescent probe used for labeling peptidoglycan in live bacteria. It integrates into the peptidoglycan biosynthesis of various bacteria.

NADA-green is a fluorescent D-amino acid that modifies and enhances the peptidoglycan layer due to the ability of D-amino acids. NADA-green efficiently integrates into peptidoglycans of a wide range of bacterial species and dopes at the site of active peptidoglycan synthesis, thereby specifically detecting bacterial growth in a covalently bound manner while minimizing interference. [1]
The peak excitation is about 450 nm and the peak emission is about 555 nm.[1]