Basophils are a type of granulocytes that are found in a very low quantity in the body. Granulocytes are the most common type of white blood cells present in the human body which account for almost 70 -75 % of the WBCs. The reason for such a name of these cells is because they contain small and visible granules within their cytoplasm. The visibility of these granules can be obtained by staining.

Although the basophils only account for about 1% of the WBCs, they are equally important for the immune system. They have the responsibility of secreting a chemical known by the name of histamine whenever the body encounters an infection. This chemical initiates the inflammatory reaction, increases blood flow to damaged tissues, and is used in a number of other processes going on in the body too.

Basophils also produce substances that attract neutrophils and eosinophils to a trouble spot.