Basophils simplified

"Basophils are the bomb. They are less in number and explosive."

What you need to know about this warrior -

What does a basophil look like?
It has a bilobed nucleus. It is long and ribbon like with less indentations.
It is full of  basophilic staining cytoplasmic granules.
What does that mean? @_@
When you stain cells with an H&E stain, basophils take up blue.
These little granules contain pharmacologically active substances.

What is the function of a basophil?
Basophils are nonphagocytic granulocytes.
They take part in inflammation. Basophils and mast cells, are important in allergic reactions.

About type I hypersensitivity in short:
A type I hypersensitive reaction is induced by certain types of antigens referred to as allergens, and has all the hallmarks of a normal humoral response.
How is hypersensitivty different from a humoral response?
Plasma cells secrete IgE in a hypersensitivity reaction.
On first exposure to an allergen:
IgE binds with high affinity to Fc receptors on the surface of tissue mast cells and blood basophils.
Mast cells and basophils coated by IgE are said to be sensitized.
A later exposure to the same allergen:
Cross-links the membrane-bound IgE on sensitized mast cells and basophils, causing degranulation of these cells. (Causing them to explode, like a bomb!)

What is the normal basophil count?
Less than 1%

That's all!