TORONTO -- A Nobel Prize winner has admitted she “did not do her job well” after a scientific paper published last year was retracted.

American Frances Arnold won the Nobel Prize for chemistry in 2018 “for the directed evolution of enzymes.”

In a series of tweets on January 2, she revealed a different paper, published May 2019, has been pulled from the highly-respected “Science” magazine.

“For my first work-related tweet of 2020, I am totally bummed to announce that we have retracted last year's paper on enzymatic synthesis of beta-lactams,” Arnold tweeted.

“The work has not been reproducible. It is painful to admit, but important to do so. I apologize to all.

“I was a bit busy when this was submitted, and did not do my job well.”

The paper, titled “Site-selective enzymatic C‒H amidation for synthesis of diverse lactams,” was published with co-authors Zhi-Jun Jia and Inha Cho.

A notice in the journal said efforts to try and reproduce the work of Arnold, Jia and Cho had failed, essentially proving it wrong. 

“Efforts to reproduce the work showed that the enzymes do not catalyze the reactions with the activities and selectivities claimed,” the note read.

“Careful examination of the first author's lab notebook then revealed missing contemporaneous entries and raw data for key experiments. The authors are therefore retracting the paper.”

But other scientists were quick to commend Arnold, who works at the California Institute of Technology and sits on the board of directors at Google parent company Alphabet, for admitting her mistake.

“Sometimes things appear to work, then they don’t. Science should be a process, not winner takes all whatever the cost,” wrote Professor Lee Cronin from the University of Glasgow in Scotland.

“Entrepreneurs are encouraged to fail well, but in science it’s still taboo. I hope when I slip up I’m able to do it so openly and well.”

Indian scientist Anmol Kilkarni also praised Arnold for her honesty.

“Seeing a Nobel laureate tweet about a paper retraction teaches how important it is for scientist to be honest about their data,” he tweeted.

“For someone like me who is just starting out in the field of research, your act teaches an important lesson.”