But after a review of the journal's files, the editors say they have concluded that the original manuscript contained 11 different photos and that the set with the erroneous duplicates was sent by the authors after Science had requested higher-resolution photos. 「操作」したのはScience側ではないってことですね。好意的(楽観的)に考えると、最初の原稿に 載った写真の高解像度バージョンが全てそろわなかったので、「仕方なく」、他の細胞の写真を 加工してそれらしく見せた、ということですか? うーん
All the photos were prepared in Seoul and sent to Dr. Schatten in Pittsburgh, who forwarded them to Science. It is not yet clear if the mix-up occurred in Seoul or in Pittsburgh. where Dr. Schatten copied the photos, said Jane Duffield, a spokeswoman at Pittsburgh. Though all the research was done in Seoul, Dr. Schatten's role was to correct the English and serve as a consultant, she said.
Recently serious controvery erupted over a thesis by Woo-Suk Hwang reported in Science in that surprising similarities can be found in the DNA fingerprinting patterns amongst the contrast groups of donor cells and stem cells. Those graphs appear in the supplementary figures of the same article.
If the intensity of fingerprinting peaks are of the same magnitude, it can mean that PCR products' concentration for each marker is exactly the same since every marker must have been magnified at the same rate. We can obtain this result by injecting identical samples twice. We can never get the Dr. Hwang's result where two identical photos can be exactly superimposed even after two identical samples were injected. They must be a bit different. The reason is that analyses by machines must needs show genuine signals along with different levels of noises from the machine.
(>>177の続き) Let's suppose we analyze extracted DNAs from donor stem cells by multiplex PCR . Obviously the number of cells in the two different samples is different; the efficiency when DNAs are extracted must be different, so must be the PCR efficiency. Additionally, the impurity concentration that normally hampers PCR process must be different as well.
These unavoidable variables bring about a result where the peaks are correspondingly located at identical spots. However precise a measurement of DNA amount may be made and PCR may be performed, the relative ratios of PCR products, i.e., the ratios of peak magnitude, can never be identical if indepent experiments are performed with two different samples. It is because the primer PCR efficiency that magnifies each marker can fluctuate according to the separated states of template DNAs. That is the main reason why we do compare not the magnitude(intensity) but the location of each peak to evaluate identical material. I sincerely hope the argument so far can be made understood despite the language barrier.
(>>179の続き) However, the two results that show relative differences in peak ratios mean there were two different experiments of DNA extraction and independently performed PCR. In contrast, the fact that relative peak ratios are almost identical means there has been only one DNA extraction and one PCR performance, all of which derive from the same sample.
An obvious conclusion is there have never been stem cells or there were no such things as donor cells. Even the most reserved observation would be that the number of stem cells believed to have been made by Dr. Hwang's team does not correspond to that of the similar DNA fingerprinting patterns.
The controversy and discussion in the community of Korean scientists has been helpful in understanding the Dr. Hwang's much fanfared achievements. Unfortunately however, in the name of "Veri Tas Lux Mea", we have no option but to ask Your Honorable Editorial Scientists to delve into this matter and initiate a thorough investigation into Dr. Hwang's article. Our own procedural self-policing system in South Korea has already set in motion, but independent investigation would be desirable.