Eosinophilic vs Basophilic: How to tell the difference

You're probably here because the words eosinophilic, acidophilic and basophilic keep coming up in texts, and you are utterly confused at this point. As a former medical student, I share that pain, and I have created this article to clear this out for you once and for all. Check out the other article for more details on the systematic approach to identifying and describing histological slides. Now get ready for the ultimate showdown: Eosinophilic Vs Basophilic? What's the difference? You're soon going to find out!

H&E Stain

Before we understand those terms, we need to learn about what gives rise to all of these above mentioned characteristics that confused us so much. Haematoxylin and eosin stain, or H&E stain, is a vital tissue stain in histology. It's widely used in medical diagnosis, often considered the gold standard. Haematoxylin is acidic, and eosin is basic in nature. Bases are neutralized by acids. Therefore, the basic dye stains structures that are acidic in nature. This indicates that basophilic cells contain a lot of acids, and vice versa.

• Basophilic structures appear in deep blue colour.
• Eosinophilic structures appear in light pink colour.

Eosinophilic or acidophilic cells prefer the acidic dye, Eosin. As a result, they absorb more of this dye than Haematoxylin and can be observed in histological sections in light pink colour. Structures that absorb acidic dye are basic in nature because bases attract acids. Eosinophilic structures, in general, consist of protein, such as collagen.

Basophilic Components in Tissues

• Nucleic Acids
• Heterochromatin -nucleolus)
• RNA – Ribosome, Rough Endoplasmic Reticulum (RER)
• Chondrin – Cartilage

Eosinophilic (Acidophilic) Components in Tissues

• Intracellular membranes
• Cellular protein filaments - Actin and Myosin in muscle fibres,
• Extracellular proteins – Collagen

Comparison: Acidophilic Vs Basophilic