Nonyl acridine orange *CAS 75168-11-5*

10-n-Nonyl acridine orange (NAO) is a mitochondrial-specific fluorochrome. In contrast with Rh 123, NAO accumulation in the cell does not seem to be driven by the proton-motrice force but does seem to be related to specific interactions with mitochondrial membrane proteins and/or lipids. NAO uptake is independent of mitochondrial transmembrane potential. It is used to examine the changes in the mitochondrial compartment during the transfer of articular chondrocytes from cartilage to the culture conditions, where Rh 123 proves changes in mitochondrial activity and/or biogenesis. It is used for distinguishing mitochondrial activity from biogenesis. NAO and Rhodamine 123 (Rh 123) is a good pair of dyes for studying mitochondrial functions.