The already beleaguered stem cell research community in the United States received another blow in August, when billionaire entrepreneur Jim Clark suspended payment towards a biomedical centre in protest against the US Government's restrictions placed upon stem cell research.

Clark stated in a letter to the New York Times that he was suspending his remaining $60 million pledge to Stanford University in response to the decision to restrict federally funded research to the 64 cell lines that are already known to exist.

“I can say that with no prospect of federal support, significant scientific inquiry in a field like stem cell research will stop. No research leader can forgo federal money”, Clark wrote. The situation may, in fact, be worse as US Government officials now estimate there might only be around 25 lines that are actually available.

Clark, the founder of Netscape and a former electrical engineering professor at Stanford, had originally committed $150 million towards the James H. Clark Center for Biomedical Engineering and Sciences, for research into the convergence of engineering and molecular biology.

But restrictions on stem cell research means US scientists risk “being thrown into a dark age of medical research”, Clark argues.

Many US scientists agree. Last month, a report on the state of human stem cell science by a National Academy of Sciences committee, headed by Bert Vogelstein, strongly supported federal financing for stem cell research, although it did not directly address the Government's policy.