bioethics

Scientists want to study stem cells in the laboratory so they can learn about their essential properties and what makes them different from specialized cell types.

stem cells

Scientists want to study stem cells in the laboratory so they can learn about their essential properties and what makes them different from specialized cell types.

In the developing fetus, stem cells in developing tissues give rise to the multiple specialized cell types that make up the heart, lung, skin, and other tissues. In some adult tissues, such as bone marrow, muscle, and brain, discrete populations of adult stem cells generate replacements for cells that are lost through normal wear and tear, injury, or disease.

Such information is critical for scientists to be able to grow large numbers of unspecialized stem cells in the laboratory for further experimentation. Stem cells can give rise to specialized cells. When unspecialized stem cells give rise to specialized cells, the process is called differentiation.

Human embryonic stem cells are isolated by transferring the inner cell mass into a plastic laboratory culture dish that contains a nutrient broth known as culture medium. The cells divide and spread over the surface of the dish.

This coating layer of cells is called a feeder layer. The reason for having the mouse cells in the bottom of the culture dish is to give the inner cell mass cells a sticky surface to which they can attach.