A ratiometric fluorescent probe for monitoring pH fluctuations during autophagy in living cells.

We present a ratiometric fluorescent probe for monitoring pH featuring superb photostability and chemostability. The down-regulation of the intracellular pH during autophagy in living cells induced by various stimuli, including several drugs and starvation, was quantified, which could provide instructive value to construct autophagy models to study the related pathological processes.