Sudan IV, also known as Sudan 4 or Solvent Red 24, is a fat-soluble disazo dye used to stain lipids, particularly neutral triglycerides in frozen tissue sections. As a lysochrome, it stains through preferential dissolution in lipid rather than chemical bonding to the specimen.
The dye imparts red to orange-red coloration to lipid-rich regions. Staining intensity and contrast depend on the solvent formulation, specimen preparation, and differentiation conditions.
Frozen sections are the principal preparation type for triglyceride staining. Sudan IV can also stain some protein-bound lipids in paraffin sections, depending on the tissue preparation and staining method.
Key Properties
- Product number: 14516
- CAS number: 85-83-6
- Molecular formula: C24H20N4O
- Molecular weight: 380.5g/mol
- Physical form: Solid
- Fat-soluble disazo dye (lysochrome)
- Used predominantly to stain triglycerides in frozen tissue sections
- Visible absorption maximum: Approximately 520nm in chloroform
- Related names: Sudan 4; Solvent Red 24; Scarlet Red; Oil Red IV
Applications
Neutral Lipid Staining
Sudan IV stains neutral lipids, particularly triglycerides, in frozen tissue sections. The dye preferentially dissolves in lipid-rich regions, producing red to orange-red contrast.
Histological Lipid Demonstration
Sudan IV is used to visualize lipid-containing structures in tissue sections. In paraffin sections, its application is limited to lipids retained during processing, including some protein-bound lipids.
Tissue Specimen Staining
Sudan IV is used in research methods for staining lipid-rich regions in tissue specimens. Select the solvent formulation, staining time, and differentiation conditions appropriate to the specimen and analytical objective.
Staining Behavior & Preparation Considerations
- Stains through preferential dissolution in lipid rather than chemical bonding
- Produces red to orange-red coloration in stained lipid material
- Used primarily on frozen sections for triglyceride staining
- Can stain some protein-bound lipids in paraffin sections, depending on tissue preparation
- Staining solutions can be prepared in isopropanol or ethanol/acetone mixtures, depending on the protocol
- Solution formulation and differentiation conditions affect staining intensity and background
- Visible absorption maximum is approximately 520nm in chloroform
Storage & Product Selection
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FAQ
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1. What is Sudan IV?
Sudan IV is a fat-soluble disazo dye used for lipid staining, particularly the demonstration of neutral triglycerides in frozen tissue sections. It is also known as Sudan 4 and Solvent Red 24.
2. What does Sudan IV stain or test for?
Sudan IV demonstrates lipid material, particularly neutral triglycerides. It preferentially dissolves in lipid-rich regions, producing red to orange-red coloration. Interpretation depends on the specimen and staining method.
3. What color does Sudan IV produce in lipid staining?
Sudan IV produces red to orange-red coloration in stained lipid material. The shade and intensity depend on the solvent formulation, specimen preparation, and differentiation conditions.
4. How does Sudan IV stain lipids?
Sudan IV is a lysochrome, or fat-soluble dye. It stains through preferential dissolution in lipid rather than chemical bonding to the specimen.
5. Can Sudan IV be used on frozen and paraffin sections?
Sudan IV is used primarily to stain triglycerides in frozen sections. In paraffin sections, it can stain some protein-bound lipids retained during processing. The preparation method determines which lipids remain available for staining.
6. Is this product a prepared Sudan IV solution?
No. This product is a solid dye used to prepare Sudan IV staining solutions. Depending on the protocol, solutions may be prepared in isopropanol or ethanol/acetone mixtures. Follow your protocol's solvent composition and dye concentration.
7. What is the molecular weight and CAS number of Sudan IV?
Sudan IV has a molecular weight of 380.5g/mol, the molecular formula C24H20N4O, and CAS number 85-83-6.
8. How should Sudan IV be stored, and where can I obtain its SDS?
Store the reagent in a cool, dry area. Contact Polysciences to request the current Safety Data Sheet for Sudan IV, catalog 14516.
