In
genetics,
somatic cell nuclear transfer is a technique for
cloning.
The
nucleus of a
cell contains the
DNA of an
organism, which acts as its
blueprint. By removing the nucleus of a cell and replacing it with a nucleus from another cell, the former starts using the blueprint for the latter, thus transforming itself and all cells that derive from it via
cell division.
The stress on both the cell and the nucleus are enormous, which leads to a high mortality rate of recipient cells. As the procedure currently cannot be automated, but has to be performed manually under a
microscope, somatic cell nuclear transfer is very resource-consuming.
As the donor cell is a somatic cell, it has to be artificially "activated" to start working as a fertilized egg cell, thus growing into a whole organism. The biochemistry involving this activation is far from understood.
Also, not all genetic information of the donor cell is transfered. DNA of organelles (mostly mitochondria) is not moved together with the nucleus, but remains that of the recipient cell.