Sudan III is a lysochrome and diazole dye used for staining lipid. It is less popular than Oil Red O as it has a more orange shade.

Store at room temperature.

Protocol for fat staining in animal tissue sections: 1. Prepare a saturated stock solution of Sudan III in 99% isopropanol. 2. Dilute 6 ml of the stock solution with 4 ml of water. Mix well and incubate for 5-10 minutes and then filter the solution as Sudan III working solution. Note: This work solution can be used for several hours. 3. Stain thin frozen sections with Sudan III working solution for 10 minutes. 4. Wash the sections with water. 5. Counterstain in 0.1% acid alum hematoxylin for 5 minutes. 6. Place the sections in 1% aqueous Na₂HPO₄ or in water, until a blue color is seen. 7. Mount the sections with a suitable aqueous mounting medium.

Sudan III is a lysochrome and diazole dye used for staining lipid. It is less popular than Oil Red O as it has a more orange shade.