Eosin Y, 0.5% alcoholic solution, Acidic is a ready-to-use cytoplasmic counterstain for hematoxylin and eosin (H&E) staining in histology and cytology. The formulation contains acetic acid and is designed for use with hematoxylin nuclear stains in both manual and automated staining workflows.
Related names: Eosin Y solution; alcoholic eosin; acidic Eosin Y; H&E eosin counterstain.
This 0.5% alcoholic formulation does not contain isopropanol or methanol. When used after hematoxylin staining and bluing, Eosin Y provides pink cytoplasmic contrast while hematoxylin-stained nuclei remain blue.
The stain can be paired with hematoxylins such as Harris Hematoxylin, Gill's Hematoxylin #2, or Gill's Hematoxylin #3. For additional H&E workflow options, see the Eosins & Hematoxylins collection.
Key Properties
- 0.5% alcoholic Eosin Y counterstain
- Acidic formulation containing acetic acid
- Does not contain isopropanol or methanol
- Ready to use in manual and automated staining workflows
- Used as a cytoplasmic counterstain with hematoxylin
- Density: 1.07 g/cm3 at 25°C
Applications
Hematoxylin & Eosin Staining
Eosin Y, 0.5% alcoholic solution is used after hematoxylin staining and bluing in routine H&E procedures. Eosin provides pink cytoplasmic staining that contrasts with the blue nuclear staining produced by hematoxylin.
Automated Histology Staining
The ready-to-use formulation is compatible with automated H&E staining workflows. Polysciences has evaluated the stain with multiple automated staining systems using Harris Hematoxylin and Gill's hematoxylin formulations.
Manual Histology Staining
Eosin Y may also be used in manual H&E procedures for paraffin and frozen tissue sections. Staining time should be adjusted according to section thickness, hematoxylin formulation, desired eosin intensity, and subsequent alcohol differentiation.
Cytology Counterstaining
The 0.5% acidic Eosin Y formulation is also used as a cytoplasmic counterstain in cytology workflows, including Papanicolaou-type staining procedures when incorporated into an established laboratory protocol.
Compatibility & Bonding Considerations
Final eosin intensity depends on section thickness, staining time, reagent condition, hematoxylin and bluing steps, and the duration of subsequent alcohol rinses. Keep staining and processing conditions consistent when comparing specimens.
Application Tips
- Use the stain as supplied; routine dilution or reagent addition is not required
- In a manual Polysciences H&E procedure, Eosin Y is applied after hematoxylin staining, bluing, washing, and transfer through 95% alcohol
- Adjust eosin exposure according to section thickness and the desired cytoplasmic staining intensity
- Control subsequent alcohol rinses because prolonged exposure can reduce eosin staining intensity
- Maintain consistent staining times and reagent condition when comparing slides between staining runs
For manual and automated H&E procedures, staining times, and workflow guidance, refer to the Comparison of Hematoxylin and Eosin Stains on Automated Stainers Technical Data Sheet. Additional product-selection information is available in the Eosin & Bluing Reagents guide.
Handling & Storage
- Store at room temperature with the container tightly closed
- Keep away from heat, sparks, open flames, and other ignition sources
- Use with good laboratory ventilation or in a chemical fume hood
- Wear protective gloves and appropriate eye protection when handling the solution
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FAQ
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1. What is Eosin Y, 0.5% alcoholic solution used for?
It is used primarily as a cytoplasmic counterstain with hematoxylin in H&E histology and cytology staining. After hematoxylin staining and bluing, Eosin Y provides pink coloration to cytoplasmic structures.
2. Is this Eosin Y solution acidic?
Yes. This 0.5% alcoholic Eosin Y formulation contains acetic acid. Researchers who require an alcoholic formulation without acetic acid can consider Eosin Y, 1% alcoholic solution, Non-Acidic.
3. Does this Eosin Y solution contain methanol or isopropanol?
No. The acidic 0.5% alcoholic formulation does not contain methanol or isopropanol. Additional formulation and product information is available in the Eosin & Bluing Reagents guide.
4. Can Eosin Y, 0.5% alcoholic solution be used with automated stainers?
Yes. The stain is ready to use in automated staining workflows. The Hematoxylin and Eosin automated staining guide includes evaluated procedures and staining times for multiple automated stainer configurations.
5. What sizes of Eosin Y, 0.5% alcoholic solution are available?
Eosin Y, 0.5% alcoholic solution, Acidic is available in 500 mL, 1000 mL, and 3.75 L sizes. For quantities beyond the listed package sizes, request a bulk quote.
Safety & Documentation
Eosin Y, 0.5% alcoholic solution, Acidic is a flammable liquid. Use appropriate laboratory ventilation, protective gloves, and eye protection, and keep the reagent away from ignition sources. Review the Safety Data Sheet (SDS) for complete safety and handling information, the product specification for current quality requirements, and the Technical Data Sheet for manual and automated H&E staining guidance.
