Protonex^™ Red 600

Protonex™ Red 600 is a pH-dependent dye. It can be used in conjunction with additional dyes for multi-labeling purposes. Protonex™ Red 600 displays excitation/emission maxima of 576/597 nm, respectively, with high fluorescence intensity in acidic pH environments, such as phagosomes, endosomes, and lysosomes, but only weakly fluoresces in the extracellular environment. It can be used for fluorescence microscopy and flow cytometry applications. Protonex™ Red 600 has been used to measure intracellular acidity levels in isolated mouse bone marrow-derived macrophages (BMDMs).¹

ASSAY PROTOCOL

Note: This protocol should be used as a guideline and modified according to the user's specific needs. Treat cells as desired prior to making the Protonex™ Red 600 working solution.
1. Prepare a 1-10 mM Protonex™ Red 600 stock solution in DMSO.
2. Treat cells as desired.
3. Prepare a 0.1-10 µM Protonex™ Red 600 working solution by diluting the DMSO stock solution into HEPES-buffered Hanks' balanced salt solution (HHBS) or a similar buffer.
4. Incubate the cells with Protonex™ Red 600 working solution for 15-120 minutes at 37°C.
5. Replace the dye-loaded solution with HHBS or a similar buffer.
6. Analyze the cells by fluorescence microscopy or flow cytometry.

WARNING This product is not for human or veterinary use.

1. Qiu, J., Zheng, X., Ye, J., et al. The V-ATPase a3 subunit deficiency affects osteoarthritis via mTOR-mediated autophagy levels in subchondral bone. Biochem. Pharmacol. 241, 117180 (2025).