SEOUL, South Korea -- A former colleague of South Korean scientist Hwang Woo-suk said Saturday he will test laboratory samples to determine if all of the stem-cell lines in Hwang's research were faked.
Roh Sung-il, whose name appears on the scientific article that made the research findings known, also told The Associated Press he wasn't aware of the paper until it appeared in the journal Science in May.
"Usually a paper is circulated between co-authors before it gets published," Roh said. "But due to security concerns, the paper was written just between Professor Hwang and Professor Gerald Schatten," a University of Pittsburgh researcher who worked closely with Hwang before severing ties over ethics lapses in Hwang's research.
Hwang on Friday acknowledged "fatal errors" in the May article and said he has asked Science to withdraw the paper, which purported to show how his team created custom-made embryonic stem cells for 11 patients.
In a nationally televised news conference, the Seoul National University scientist admitted there were only eight stem-cell lines when he submitted the paper for review, but that his team later created three more. He added that tests on his stem cell lines will prove his team "has the source technology to produce them."
Roh, who has said nine of the 11 stem cell lines were fabricated, said Saturday he would conduct his own test to determine if the other two are also fake.
Samples of the two stem-cell lines that Hwang's team created and stored at the Mizmedi Hospital were in the nurturing stage and tests will prove "if they are patient-specific stem cells from cloned embryos," Roh told AP.
"But to be honest, I am not sure if these samples are the same ones at Seoul National University," said Roh, chairman of the board at the hospital.
At Friday's news conference, Hwang claimed some of the stem-cell colonies his team has created have been replaced by those created by Roh's hospital, and called for an investigation. Roh said the allegation is meant to pin the fraud on another ex-colleague of Hwang's who works at the hospital.
The researcher, Kim Sun-jong, told South Korean media that Hwang had ordered him to fabricate data to make it look like there were 11 stem-cell colonies, instead of just two.
"Making two appear 11 is a fabrication," Kim told the JoongAng Ilbo daily on Friday. "That is why there is the problem of (duplicate) photos ... and I say the paper was faked."
Hwang's team earlier told Science some duplicate photos of the same stem cell colonies were accidentally printed in the journal and presented as separate colonies, a mistake the editors have said did not affect the findings.
Kim -- who is now at the University of Pittsburgh -- said he had personally seen eight completed stem-cell lines while working with Hwang. Kim said he didn't know about Hwang's allegation that some of his stem-cell lines have been switched.
"I have nothing to (gain) from switching the stem cells," Kim told reporters, according to Yonhap news agency Saturday. "Why would I do such a thing?"
Hwang had become a national hero in South Korea for his stunning scientific claims, which also including the world's first cloned human embryos and the world's first cloned dog -- achievements that have not been directly questioned.
Last month, Hwang publicly admitted that, after more than a year of denial, he had violated international ethics guidelines by using eggs from two female scientists in his lab. He also then stepped down as head of the World Stem Cell Hub, an international project launched in October and aimed at finding treatments for incurable diseases.
