Eosin Y in Staining

Eosin Y

• Eosin Y is the most widely used due to its solubility in alcohol.
• It is typically used as a 0.5 or 1% solution in DI water with a crystal of thymol added to inhibit fungal growth.
• Adding 0.5 ml of acetic acid to 1000 ml of stain solution can sharpen the staining.

Staining Procedure for H&E

• The procedure consists of 9 steps: dewaxing, hydration, hematoxylin, differentiation, bluing, eosin, dehydration, clearing, and cover-slipping.

Preparation of Wax Sections for Staining

• Dewaxing is necessary to remove wax from sections, as wax hinders the reaction of dyes with tissues and renders them impermeable to stains.
• Xylene is used as a clearing agent, and heat can be incorporated to speed up the reaction.
• Sections must be dry before immersing them in xylene.

Hydration

• Immerse sections in decreasing concentrations of alcohol (100% → 90% → 70% → water) to remove the clearing agent.
• Replaced cloudy alcohol solutions with fresh ones.

Procedures After Staining

• It is essential to mount the stained section with a mounting agent to preserve the tissue and increase the refractive index for viewing under a microscope.

Mounting Procedures

• Dehydration: remove water from the stained section by immersing it in a series of alcohols (70% → 90% → absolute alcohol) to prevent distortion of the tissue.
• Clearing: remove alcohol with xylene, which raises the refractive index of the section.
• Mounting: use a mounting agent (DPX) to permanently preserve the stained section, ensuring no bubbles are trapped.

Learn about the properties and uses of Eosin Y, a popular stain in laboratory settings, including its solubility, concentration, and additives.