Safranin O (Basic red 2) stains the lignified, embolic and keratinized parts of the plant, as well as chromatin and chromosomes in the nucleus. Safranin O is commonly used for the detection of cartilage, mucin and mast cell granules.

Instructions
1. Solution preparation:
Dissolve DEAC, SE in anhydrous dimethyl sulfoxide (DMSO) to prepare a stock solution of the required concentration.
The recommended stock solution concentration is 10 mM for subsequent dilution.
2. Labeling process:
1) Dissolve the biomolecule to be labeled (such as protein or peptide) in an appropriate amine-free buffer (such as carbonate buffer, pH 8.3).
2) Add an appropriate amount of DEAC, SE stock solution to the above solution, usually reacting at a dye to biomolecule molar ratio of 5:1 to 20:1.
3) Incubate at room temperature in the dark for 30 minutes to 1 hour to ensure sufficient reaction.
3. Purification: After the reaction is completed, use an appropriate purification method (such as gel filtration, dialysis or high-performance liquid chromatography) to remove unreacted dye.
4. Detection: Use a fluorescence spectrometer or fluorescence microscope for detection. The excitation wavelength of DEAC, SE is about 355 nm and the emission wavelength is about 445 nm.
Notes:
1) Wear gloves during operation to avoid contact between skin or mucous membrane and reagent.
2) Avoid light exposure during incubation and storage to prevent fluorescence quenching.
3) After staining, fluorescence detection and analysis should be performed immediately.