What 'we're discussing today hasn't been published in a single scientific journal,' said Sen. Tom Harkin of the stem-cell alternative proposal backed by conservatives. 'It hasn't even cleared the peer review process. It hasn't been tried in mice. We're a long way from proving it works with human embryos.'

"I'm all for these alternative sources ... let's go ahead and pursue them. But we already know how to derive stem cells," said Sen. Tom Harkin, D-Iowa. Harkin, with Sen. Arlen Specter, R-Pa., is sponsoring a House-passed bill to lift Bush's restrictions on stem cell research.

Testifying Tuesday were four scientists whose alternative research is being considered by Bush, Senate Majority Leader Bill Frist and other conservatives who want to vote for embryonic stem cell legislation that does not destroy budding human life.

Frist, R-Tenn., wants to bring up four to five such bills as alternatives to Specter-Harkin to give senators a way to vote for embryonic stem cell research without crossing constituents who harbor moral concerns.

While interesting, the methods aren't worth funding without passing the Specter-Harkin bill, the '

Robert Lanza, vice president of medical and scientific research for Advanced Cell Technology, which is developing one type of alternative research, called any choice between the Specter-Harkin bill and a conservative alternative that might fund his own studies "a no-brainer." No-

"We need to pass (H.R.) 810," he said, referring to the House- passed version. "I do not think we should keep the scientific community or the patient community waiting."

But William B. Hurlbut of Stanford University told the panel that Congress should first support bills on which there is ethical consensus and provide "a coherent moral platform to guide our science."

Harkin didn't budge.

What "we're discussing today hasn't been published in a single scientific journal," Harkin said. "It hasn't even cleared the peer review process. It hasn't been tried in mice. We're a long way from proving it works with human embryos."

Harkin said that "if we're going to fund these alternative approaches, that's fine -- if we don't stop the process that we have right now of deriving embryonic stem cells that have so much promise for cures."