STEM CELLS

What is a stem cell?

A stem cell is a cell with the unique ability to develop into specialised cell types in the body. In the future they may be used to replace cells and tissues that have been damaged or lost due to disease.

What is a stem cell?

• Our body is made up of many different types of cell^?.
• Most cells are specialised to perform particular functions, such as red blood cells^? that carry oxygen around our bodies in the blood, but they are unable to divide.
• Stem cells provide new cells for the body as it grows, and replace specialised cells that are damaged or lost. They have two unique properties that enable them to do this:
  • They can divide over and over again to produce new cells.
  • As they divide, they can change into the other types of cell that make up the body. 

An illustration showing a stem cell giving rise to more stem cells or specialised cells.
Image credit: Genome Research Limited

Different types of stem cell

• There are three main types of stem cell:
  • embryonic stem cells
  • adult stem cells
  • induced pluripotent stem cells

Embryonic stem cells

• Embryonic stem cells supply new cells for an embryo^? as it grows and develops into a baby.
• These stem cells are said to be pluripotent, which means they can change into any cell in the body.

Adult stem cells

• Adult stem cells supply new cells as an organism grows and to replace cells that get damaged.
• Adult stem cells are said to be multipotent, which means they can only change into some cells in the body, not any cell, for example:
  • Blood (or 'haematopoietic') stem cells can only replace the various types of cells in the blood.
  • Skin (or 'epithelial') stem cells provide the different types of cells that make up our skin and hair.

An illustration showing different types of stem cell in the body.
Image credit: Genome Research Limited

Induced pluripotent stem cells

• Induced pluripotent stem cells, or ‘iPS cells’, are stem cells that scientists make in the laboratory.
• ‘Induced’ means that they are made in the lab by taking normal adult cells, like skin or blood cells, and reprogramming them to become stem cells.
• Just like embryonic stem cells, they are pluripotent so they can develop into any cell type