Obtaining stem cells

How are stems cells obtained?

In order for stem cells to be cultivated, the pluripotent cells have to be alive. It must have the potential to be multiplied. The source of the cell must also be alive. This is therefore, very difficult to obtain suitable pluripotent cells.

There are four ways to get embryos:

Fertility Clinics

During in-vitro fertilization, clinics routinely fuse more than one egg with sperm. That way, if implanting a fertilized egg doesn't work the first time, they can try again. This practice has left thousands of unwanted embryos stored in clinic freezers. James Thomson, the first scientist to establish a human stem-cell line, used such embryos. (See diagram on the right)

Aborted Fetuses

John Gearhart, the Johns Hopkins biologist credited, along with Thomson, with first culturing stem cells, extracted his from fetuses donated by women at a nearby abortion clinic. (see diagram on the right)

Cloning

Advanced Cell Technology of Worcester, Mass., acknowledged last week that it is trying to create cloned human embryos as sources for stem cells. The company has considered selling its stem cells to other researchers.

Made to Order

The Jones Institute in Virginia, where the first U.S. test-tube baby was conceived, has mixed sperm and eggs expressly to create embryos as sources for stem cells.

Although all the methods are very different in sources, the cells cultivated turn out to be very similiar. Another way of obtaining stem cells is from the use of somatic cell nuclear transfer (SCNT). This method is being testing currently on animals. This methed fuses cells together, using the nutrients of eggs.

Adapted from: http://www.ncbi.nlm.nih.gov/About/primer/genetics_cell.html