Basophilic is a technical term used by histologists

Histology

Histology is the study of the microscopic anatomy of cells and tissues of plants and animals. It is performed by examining cells and tissues commonly by sectioning and staining; followed by examination under a light microscope or electron microscope...

. It describes the microscopic appearance of cell

Cell (biology)

The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

s and tissue

Biological tissue

Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...

s, as seen down the microscope

Microscope

A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...

, after a histological section

Histological section

Histological section refers to thin slices of tissue applied to a microscopic slide, usually around 5 to 10 micrometres thick, which are viewed under a microscope...

 has been stained with a basic dye

Dye

A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....

. The most common such dye is haematoxylin

Haematoxylin

Haematoxylin, hematoxylin, Natural Black 1, or C.I. 75290 is extracted from the heartwood of the logwood tree. When oxidized it forms haematein, a compound that forms strongly coloured complexes with certain metal ions, the most notable ones being Fe and Al salts. Metal-haematein complexes are used...

.

Basophilic describes the appearance of structures seen in histological sections which take up basic dyes. The structures usually stained are those that contain nucleic acid

Nucleic acid

Nucleic acids are biological molecules essential for life, and include DNA and RNA . Together with proteins, nucleic acids make up the most important macromolecules; each is found in abundance in all living things, where they function in encoding, transmitting and expressing genetic information...

 such as the cell nucleus

Cell nucleus

In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...

 and ribosomes.

Basophils are cells that "love" base

Base (chemistry)

For the term in genetics, see base A base in chemistry is a substance that can accept hydrogen ions or more generally, donate electron pairs. A soluble base is referred to as an alkali if it contains and releases hydroxide ions quantitatively...

, and which usually show up deep blue under standard staining techniques (H&E). Specifically, this term refers to:

• basophil granulocyte
  Basophil granulocyte
  Basophil granulocytes, sometimes referred to as basophils, are the least common of the granulocytes, representing about 0.01% to 0.3% of circulating white blood cells....
  
  s
• anterior pituitary basophil
  Anterior pituitary basophil
  An anterior pituitary basophil is a type of cell in the anterior pituitary which manufactures hormones.It is called a basophil because it readily takes up base, and typically stains a relatively deep blue or purple....
  
  s