One, with her eyes pressed closely to a microscope and wielding the tiniest of needles, pokes a hole in a pig egg before gently squeezing out its genetic content. Another researcher with a straw-like instrument then inserts new genetic material from the cloning candidate. Chances are, the scientists' creation in the world's most renowned cloning laboratory will turn into a thriving pig embryo.

It doesn't take much more to clone a human embryo - a technological first accomplished here last year to international clamor.

The Vatican and President Bush condemned the work. The South Korean government reacted with pride. It issued a postage stamp and handed out public funds. Gaggles of envious foreign stem cell scientists now trek continuously to Hwang's lab for lessons.

The idea is to clone human embryos not to make babies but to harvest human embryonic stem cells, which are created in the first days after conception and give rise to the human body. Scientists hope to someday use stem cells to replace and repair diseased and damaged parts of the body.

Stem cell scientists believe that cloning will offer a way around immune rejection problems when injecting living cells into patients.

At the very least, the scientists say intentionally cloning a human embryo with a disease will offer them unprecedented insight into how many illnesses develop.

And so far, nobody in the world has legitimately reported accomplishing this feat except Hwang and his crew.