Embryonic Stem Cell Researchers Question Cloning

Date: 06/12/2002

Even many scientists who support embryonic stem cell (ESC) research have expressed serious doubts that so-called therapeutic cloning will ever lead to real therapies for patients:

“[T]he poor availability of human oocytes, the low efficiency of the nuclear transfer procedure, and the long population-doubling time of human ES cells make it difficult to envision this [embryo cloning to produce stem cells] becoming a routine clinical procedure…”
–J.S. Odorico, D.S. Kaufman, J.A. Thomson, “Multilineage differentiation from human embryonic stem cell lines,” Stem Cells 19, 193-204; 2001

“…[T]he use of such therapeutic cloning to produce useful treatments may simply be impractical…’It’s too laborious and costly to employ as a routine therapeutic procedure,’ said Dr. Alan Colman, research director at”[I]t may come as a surprise that many experts do not now expect therapeutic cloning to have a large clinical impact…many researchers have come to doubt whether therapeutic cloning will ever be efficient enough to be commercially viable. ‘It would be astronomically expensive,’ says James Thomson of the University of Wisconsin in Madison, who led the team that first isolated E[mbryonic] S[tem] cells from human blastocysts.”
–“Can they rebuild us?” Nature, April 5, 2001, pp. 622-5.