What organelles reside in a Neutrophil White blood cell?

Neutrophils have the same organelles as any other mammalian cell (ER, golgi, nucleus, mitochondria, etc.), but some of these organelles have marked difference in them.

For example, the nucleus of a neutrophil typically has 2-5 lobes; originally it was thought that they had multiple nuclei (as do megakaryocytes, a type of white blood cell that make platelets), but now we know there is only one nucleus per cell, but it takes on that strange, characteristic morphology. That's why neutrophils along with basophils and eosinophils (other granulocytes) are called polymorphonuclear cells.

Otherwise,neutrophils also have specialized secretory vesicles called granuoles (that's why neutrophils are classified as granulocytes) that are released in response to various stimuli in order to fight infection. There are three types of granuoles in neutrophils: secondary granuoles, azurophillic granuoles and tertiary granuoles. All of them are filled with various cytotoxic molecules (enzymes to produce reactive oxygen species, antimicrobial peptides, etc.) in order to kill infected cells or the pathogen itself.

This granulocyte has very tiny light staining granules (the granules are very difficult to see). The nucleus is frequently multi-lobed with lobes connected by thin strands of nuclear material. These cells are capable of phagocytizing foreign cells, toxins, and viruses.


During infections, these cells divide and are dumped into the blood stream and lymph fluids to combat the infection. They fight invaders by "eating" bacteria and other foreign matter. The neutrophil membrane wraps around the invader and traps it inside the neutrophil. Once inside, digestive enzymes in the neutrophil destroy the invader.
The cell nucleus in new, young neutrophils tends to break into pieces as they age. Thus, by counting the percentage of neutrophils that have a single, intact nucleus, a doctor can know that the body is responding as expected to an infection.

Neutrophils are the most common granulocyte. They have segmented nuclei, typically with 2 to 5 lobes connected together by thin strands of chromatin which can be difficult to see; the cell may thus appear to have multiple nuclei. The nuclear chromatin is condensed into coarse clumps. Small numbers of immature neutrophils or band form neutrophils may be seen in a blood smear. These are incompletely segmented and often have a 'C-shaped' nucleus.

The cytoplasm of neutrophils contains three types of granule.

Primary granules are non-specific and contain lysosomal enzymes, defensins, and some lysozyme. The granules are similar to lysosomes. They stain aviolet colour when prepared with Wright's stain which is commonly used in studying the blood. The enzymes produce hydrogen peroxide which is a powerful anti-bacterial agent.

Secondary granules are specific to neutrophils and stain light pink ('neutral stain'). They contain collagenase, to help the cell move through connective tissue, and lactoferrin, which is toxic to bacteria and fungi.

Tertiary granules have only recently been recognised. It is thought that they produce proteins which help the neutrophils to stick to other cells and hence aid the process of phagocytosis.

Once in the area of infection neutrophils respond to chemicals (called chemotaxins which are released by bacteria and dead tissue cells) and move towards the area of highest concentration. Here they begin the process of phagocytosis in which they engulf the offending cells and destroy them with their powerful enzymes. Because this process consumes so much energy the neutrophils glycogen reserves are soon depleted and they die soon after phagocytosis. When the cells die their contents are released and the remnants of their enzymes cause liquefaction of closely adjacent tissue. This results in an accumulation of dead neutrophils, tissue fluid and abnormal materials known as pus.



A neutrophil count of 2.5-7.5 x 109/L is a standard normal range. Normally, neutrophils account for 50-70% of all leukocytes. If the count exceeds this amount, the cause is usually due to an acute infection such as appendicitis, smallpox or rheumatic fever. If the count is considerably less, it may be due to a viral infection such as influenza, hepatitis, or rubella.