CQ-Lyso 

CQ-Lyso is a lysosome-targeting chromenoquinoline. CQ-Lyso is a fluorescent probe for measuring the pH of lysosomes in living cells using only single wavelength excitation. CQ-Lyso can visualize the dynamic pH changes in lysosomes^[1].

Guidelines (The following is our recommended protocol, which is only a guide and should be modified according to your specific needs).
1. Preparation of Stock Solution^[1]:
1) Dissolve CQ-Lyso in acetonitrile to prepare a stock solution with a concentration of 1.0 mM.
2. Preparation of Working Solution:
1) Take 15.0 μL of the CQ-Lyso stock solution (1.0 mM) and add it to a mixture containing 2.1 mL of Britton-Robinson (B-R) buffer and 0.885 mL of acetonitrile to prepare a 5.0 μM working solution.
3. Specific Staining Steps:
3.1 Cell Culture:
1) Culture HeLa cells in DMEM medium supplemented with 10% fetal bovine serum and 1% penicillin at 37°C. When the adherent cells in the culture flask reach 85%-95% confluence, seed the cells into glass dishes and allow them to adhere for 24 h. Before the experiment, discard the culture medium and wash the cells three times with PBS buffer.
3.2 Staining Operation:
1) Add the 5.0 μM CQ-Lyso working solution to the above-treated cells and incubate at 37°C for 15 min.
2) Add 1.0 μM of LysoTracker®Deep Red or LysoTracker®Blue DND-22 and continue incubating at 37°C for 15 min.
3. Fluorescence Imaging:
1) Perform fluorescence imaging using an Olympus FV1000 or Nikon ARsiMP confocal microscope. For CQ-Lyso, use a 488 nm excitation light and collect fluorescence signals through the green fluorescence channel (515 - 550 nm) and the red fluorescence channel (570-620 nm, pseudocolored as yellow for clarity). For LysoTracker®Deep Red, use a 640 nm excitation light and collect fluorescence signals through the deep red/near-infrared channel (663-738 nm).

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

485.62

C₃₀H₃₅N₃O₃

2089438-23-1

Solid

Yellow to brown

C1(N=C(C2=C(OC3)C(CCCN4CCC5)=C4C5=C2)C3=C6)=C6C=C(OCCCCN7CCOCC7)C=C1

Room temperature in continental US; may vary elsewhere.

4°C, protect from light

*In solvent : -80°C, 6 months; -20°C, 1 month (protect from light)

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (protect from light). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

• [1]. Liu X, et al. Ratiometric Fluorescent Probe for Lysosomal pH Measurement and Imaging in Living Cells Using Single-Wavelength Excitation. Anal Chem. 2017 Jul 5;89(13):7038-7045.  [Content Brief]