Introduction to Hematoxylin and eosin H&E staining:

Hematoxylin and eosin stain (H&E) staining is a widely used technique in histology and pathology for visualizing cellular structures and tissues. The H&E stain is a combination of two dyes: hematoxylin and eosin. Hematoxylin stains the nuclei of cells blue-purple, while eosin stains the cytoplasm, extracellular matrix, and other structures pink. This staining technique is essential for identifying and diagnosing various diseases and conditions. In this blog post, we will discuss the principles of H&E staining and how it works.

Hematoxylin Staining:

Hematoxylin and eosin H&E staining

Hematoxylin is a basic dye that binds to acidic structures in cells, such as the nuclei. Hematoxylin is derived from the heartwood of the logwood tree. Hematoxylin staining involves the following steps:

  1. Deparaffinization: This involves removing the paraffin wax from the tissue sections using xylene or a similar solvent.
  2. Rehydration: This involves rehydrating the tissue sections using a series of alcohol solutions of decreasing concentrations.
  3. Hematoxylin staining: The tissue sections are then stained with hematoxylin solution for a specific period of time. The duration of staining depends on the tissue type and the desired intensity of staining.
  4. Differentiation: This involves removing excess hematoxylin from the tissue sections using an acidic solution, such as acid alcohol.
  5. Blueing: This involves treating the tissue sections with a weak alkaline solution, such as lithium carbonate, to enhance the blue color of the nuclei.

Eosin Staining:

Eosin is an acidic dye that binds to basic structures in cells, such as the cytoplasm and extracellular matrix. Eosin staining involves the following steps:

  1. Rehydration: This involves rehydrating the tissue sections using a series of alcohol solutions of decreasing concentrations.
  2. Eosin staining: The tissue sections are then stained with eosin solution for a specific period of time. The duration of staining depends on the tissue type and the desired intensity of staining.
  3. Dehydration: This involves dehydrating the tissue sections using a series of alcohol solutions of increasing concentrations.

Dehydration and Clearing:

After staining, the tissue sections are dehydrated using a series of alcohol solutions of increasing concentrations. This is followed by clearing the tissue sections using a solvent, such as xylene or a similar solvent. Dehydration and clearing help to remove excess water and prepare the tissue sections for mounting.

Mounting:

The final step in the H&E staining process is mounting. The tissue sections are mounted onto a glass slide using a mounting medium, such as Canada balsam or a similar medium. The mounted tissue sections are then covered with a coverslip and sealed.

What is H&E stain used for?

H and E staining helps identify different types of cells and tissues and provides important information about the pattern, shape, and structure of cells in a tissue sample. It is used to help diagnose diseases, such as cancer. Also called hematoxylin and eosin staining.

What Colours are H&E stains?

Hematoxylin has a deep blue-purple color and stains nucleic acids by a complex, incompletely understood reaction. Eosin is pink and stains proteins nonspecifically. In a typical tissue, nuclei are stained blue, whereas the cytoplasm and extracellular matrix have varying degrees of pink staining.

What are the advantages of H&E?

Ductal carcinoma in situ (DCIS) in breast tissue, cell nuclei (blue-purple), extracellular material (pink).

H&E offers stability of stained tissue lasting years without fading. H&E stain is also compatible when combined with various oxidants, mordants, and differentiating agents. H&E is reliable and simple to perform.

What is H and E staining in tissue processing?

The H&E procedure stains the nucleus and cytoplasm contrasting colors to readily differentiate cellular components. However, staining results are dependent on proper specimen processing, which involves tissue preservation, dehydration, clearing, and paraffin infiltration.

Conclusion:

Hematoxylin and eosin staining is a fundamental technique in histology and pathology for visualizing cellular structures and tissues. The H&E stain is a combination of two dyes: hematoxylin and eosin. Hematoxylin stains the nuclei of cells blue-purple, while eosin stains the cytoplasm, extracellular matrix, and other structures pink. The H&E staining process involves several steps, including hematoxylin staining, eosin staining, dehydration and clearing, and mounting. Understanding the principles of H&E staining is essential for identifying and diagnosing various diseases and conditions.

References:

1. https://health.ucdavis.edu/

What are the laboratory steps of H&E staining?

  1. Deparaffinization: This involves removing the paraffin wax from the tissue sections using xylene or a similar solvent.
  2. Rehydration: This involves rehydrating the tissue sections using a series of alcohol solutions of decreasing concentrations.
  3. Hematoxylin staining: The tissue sections are then stained with hematoxylin solution for a specific period of time. The duration of staining depends on the tissue type and the desired intensity of staining.
  4. Differentiation: This involves removing excess hematoxylin from the tissue sections using an acidic solution, such as acid alcohol.
  5. Blueing: This involves treating the tissue sections with a weak alkaline solution, such as lithium carbonate, to enhance the blue color of the nuclei.
  6. Eosin staining: The tissue sections are then stained with eosin solution for a specific period of time. The duration of staining depends on the tissue type and the desired intensity of staining.
  7. Dehydration: This involves dehydrating the tissue sections using a series of alcohol solutions of increasing concentrations.
  8. Clearing: This involves clearing the tissue sections using a solvent, such as xylene or a similar solvent.
  9. Mounting: The final step in the H&E staining process is mounting. The tissue sections are mounted onto a glass slide using a mounting medium, such as Canada balsam or a similar medium.

It is important to note that the specific laboratory steps may vary depending on the tissue type and the staining protocol used. The duration of each step may also vary depending on the staining protocol. It is essential to follow the recommended staining protocol and to use high-quality reagents to obtain accurate and consistent results.