Official reports have confirmed that the National Institutes of Health is now proposing an expansion of its definition of human embryonic stem cells, thereby allowing university researcher it funds to work with cells which have been taken from a very early human egg.

The new proposal has the potential to benefit various academic researchers and a company called Advanced Cell Technology, which has filed a request with the US Food and Drug Administration to undertake the testing of a treatment for macular degeneration, which is an eye disease. If approved, it would become one of the first clinical tests of embryonic stem cells, which were first discovered in the year 1988.

Currently, most of the human embryonic stem cell lines are generated from the blastocyst, an embryonic stage reached five days after fertilization, but the NIH is now looking to add to its list of approved cell lines those which have been created from blastomeres, cells which are generated after the fertilized egg’s first few divisions.

"We thought it made no sense to exclude these", said Lana R. Skirboll, an Adviser to the Director of the Agency.