TPE-2E N-oxide

Operating Instructions (The following is a recommended experimental protocol for reference only, which needs to be adjusted according to your specific requirements)
1. Stock Solution Preparation
1.1 Solvent: Water.
1.2 Recommended Concentration: It is generally recommended to prepare a high-concentration stock solution at 1-10 mM.
2. Working Solution Preparation
2.1 Diluent: Water.
2.2 Working Concentration: 200 μM.
2.3 Notes: Adjust the working solution concentration as needed; prepare it fresh before use.
3. Staining Procedure
3.1 Sample Type Description: Adherent cells (HeLa cells)^[1].
3.2 Incubation Conditions:
3.2.1 Incubate samples with TPE-2E N-oxide at a concentration of 200 μM for 3 h under normoxic (21% O₂) or hypoxic (0% O₂, 8% O₂) conditions.
3.2.2 Inhibition Assay: Incubate samples with 200 μM TPE-2E N-oxide and Diphenyliodonium chloride (0, 300 μM, 500 μM) under hypoxic conditions for 3 h.
3.2.3 Fluorescence Activation Mechanism: Under hypoxic conditions, fluorescence activation is triggered by intracellular reductase-mediated transformation and aggregation processes.
3.3 Washing Step: After incubation, wash samples with phosphate buffer before subsequent staining (e.g., Nile red (HY-D0718) staining).
4. Control Setup
4.1 A negative control (untreated HeLa cells) is required for flow cytometry analysis.
4.2 A normoxic condition control is required for hypoxic imaging and fluorescence signal comparison.
5. Detection and Analysis
5.1 Instrument Types: Laser scanning confocal microscope; flow cytometer; fluorescence microscope.
5.2 Excitation/Emission Wavelengths:
5.2.1 TPE-2E N-oxide: Excitation wavelength 405 nm, emission filter 430-560 nm (green fluorescence).
5.2.2 Nile red (if used): Excitation wavelength 560 nm, emission filter 580-700 nm (red fluorescence).
5.3 Result Analysis:
5.3.1 Fluorescence Intensity: No fluorescence is detected under normoxic (21% O₂) conditions; the green fluorescence intensity increases with decreasing oxygen concentration, reaching the highest level under 0% O₂ conditions; under hypoxic conditions, the fluorescence intensity decreases with increasing concentrations of Diphenyliodonium chloride.
5.3.2 Fluorescence Localization: Activated TPE-2E N-oxide localizes to lipid droplets, showing high colocalization with Nile red.
5.3.3 Fluorescence Color: Activated TPE-2E N-oxide emits green fluorescence; Nile red (if used) emits red fluorescence.

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