Related Experiment Video
Updated: Aug 26, 2025
09:46
Simultaneous pH Measurement in Endocytic and Cytosolic Compartments in Living Cells using Confocal Microscopy
Published on: April 28, 2014
15.1K
Resolving subcellular pH with a quantitative fluorescent lifetime biosensor
Joshua J Rennick1, Cameron J Nowell1, Colin W Pouton1
1Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
Nature Communications
|October 12, 2022
Summary
This study introduces pH dependant fluorescent lifetime imaging microscopy (pHLIM) combined with deep learning for precise sub-cellular pH measurement. This novel method accurately quantifies pH in vesicles, aiding drug action and disease research.
Area of Science:
- Cell biology
- Biophysics
- Pharmacology
Background:
- Sub-cellular pH is crucial for cellular processes like metabolism and drug delivery.
- Existing pH measurement methods using fluorophores are often uncertain and require multiple probes.
Purpose of the Study:
- To develop a precise and quantitative method for measuring sub-cellular pH.
- To overcome limitations of current intensity-based pH measurements.
Main Methods:
- Combined pH dependant fluorescent lifetime imaging microscopy (pHLIM) with deep learning.
- Engineered the pH-sensitive protein mApple for localization in cytosol, endosomes, and lysosomes.
- Utilized pHLIM to detect drug-induced pH changes (bafilomycin A1, chloroquine).
Main Results:
- Accurate quantification of sub-cellular pH in individual vesicles.
- Demonstrated rapid detection of pH changes induced by specific drugs.
- Showed polyethylenimine does not cause a proton sponge effect in endocytic vesicles.
Conclusions:
- pHLIM offers a simple, quantitative approach for sub-cellular pH measurement.
- This method can enhance understanding of drug mechanisms and disease progression.
- pHLIM provides a valuable tool for cell biology and drug development research.
