a-short-review-of-histology

Eosinophils:

Eosinophils are granular leucocytes
They are 12-15 microns in diameter and have a lobed nucleus
Typically the nucleus is bilobed. They represent 1-4% of white blood cells in normal peripheral blood
The cytoplasm of eosinophils contains numerous large granules which stain an orange colour with Romanovsky type stain
Eosinophils circulate in peripheral blood for between 1-10 hours then spend up to about 10 days in tissue spaces before dying
They have anti-parasite and anti-allergy functions

Eosinophils - 2:

In this image of a blood smear note the two eosinophils
Each shows a bilobed nucleus and is about 1.5 times the diameter of the red blood cells
The cytoplasm contains numerous large cytoplasmic granules which have been stained orange by the eosin stain which forms part of the Romanovsky staining method used for blood smears