OSAKA- Haruko Obokata, the lead author of Nature articles about stimulus-triggered acquisition of pluripotency (STAP), said Wednesday that she "produced the STAP cells successfully more than 200 times, and this is the truth."
Speaking at a press conference at an Osaka hotel, she explained why she has filed a complaint against state-affiliated scientific institution RIKEN's conclusion that she engaged in misconduct.
The press conference was her first public appearance since announcing the research results at the end of January, after the British science journal Nature carried articles about the findings.
At the very beginning of the press conference, Obokata, a RIKEN researcher, apologised for "my carelessness, ignorance and immaturity in the process of writing the theses on STAP cell creation which have raised much suspicion."
However, she argued against the final report made by RIKEN's investigation committee, which concluded that the core section of the documents in question contained "deliberate alterations and fabrications." She said, "I would also like to emphasise there was no deceptive motive in my completing these articles, given that legitimate experiments were conducted, and that there exists solid data as a direct result."
The investigation committee pointed out that Obokata had maintained only two laboratory notebooks recording experiments over the past three years, making it impossible to scientifically verify what kind of experiments she had performed.
Obokata explained, "Although I submitted two notebooks to the investigation committee, there are, in fact, more."
On April 1, the committee concluded that an image of genes said to indicate that STAP cells had been produced from the blood cells of a mouse had been fabricated, as this was actually a composite of two separate images.
In the complaint filed by Obokata, she said she admitted she had processed the image but denied fabrications, saying, "Whether or not the image was a composite, the conclusion that can be drawn from data is unchanged."
The committee also concluded that alterations and fabrications had been made to images purporting to show that STAP cells have the capacity to develop into various kinds of cells, because the images looked almost identical to others taken from experiments conducted under completely different conditions that had been used in Obokata's doctoral thesis.
On this point, Obokata and her attorneys explained that genuine images of data exist, and that she had mistakenly used the wrong images.
Disatisfaction was also expressed on the RIKEN investigation committee's structure, with Obokata insisting that the committee have "made an error in judgment based on preconceived ideas." Obokata and her attorneys are seeking a reinvestigation by a committee from which RIKEN officials-such as its own researchers-have been removed and replaced entirely by outside experts.