Contamination blamed in STAP stem cell debacle

Investigation finds new form of flexible cells were really embryonic stem cells

Mouse embryo

Researchers who claimed to have grown a mouse fetus from stem cells made in acid baths were actually working with embryonic stem cells, an investigation finds.

H. Obokata

The discredited stem cells known as STAP cells were ultraflexible because they were really embryonic stem cells, a new report contends.

Last January, researchers claimed in two papers published in Nature that they had made stem cells by briefly dipping adult cells in a dilute acid bath or by giving the cells a squeeze (SN: 2/22/14, p. 6). The research was soon called into question, and an investigation by RIKEN, the Japanese research institute where much of the work was done, found lead author Haruko Obokata guilty of manipulating images and plagiarizing parts of the text. The papers were retracted in July (SN: 7/26/14, p. 7).

After months of failing to replicate her work, Obokata resigned and RIKEN said it would cease efforts to re-create the cells.

On December 26, RIKEN issued a report saying that what the researchers claimed were STAP cells were really embryonic stem cells contaminating the lab dishes. The contamination probably wasn’t accidental, but exactly who was responsible for it could not be determined. The investigators found Obokata guilty of two more counts of misconduct for fabricating data.

The report may close the book on a year-long saga that has marred stem cell science (SN: 12/27/14, p. 25).

Tina Hesman Saey is the senior staff writer and reports on molecular biology. She has a Ph.D. in molecular genetics from Washington University in St. Louis and a master’s degree in science journalism from Boston University.

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