Detained over frog embryos: Why this Russia-born Harvard scientist’s arrest in Boston could stall a major medical advance

A Harvard scientist integral to a promising breakthrough in cancer diagnostics has spent the past two months in an immigration detention centre, sparking fears that her absence could stall crucial advances in early detection technology, NBC News reported.
Kseniia Petrova, 30, a Russian-born researcher at Harvard Medical School’s Kirschner Lab, was detained by US immigration authorities in February at Boston’s Logan Airport for allegedly failing to declare scientific materials — frog embryo samples — used in her research. She is currently being held at the Richwood Correctional Center in Louisiana and faces possible deportation to Russia, where she says she could face imprisonment for protesting against the war in Ukraine.
Petrova developed complex computer scripts essential for analysing data generated by a groundbreaking microscope used in Harvard’s cancer and longevity studies. “Without her, I fully believe that all the insights into cures or fundamental biology that we could make will not be made,” said her colleague and housemate, Dr William Trim. “I’m very confident she is the only way we can achieve the true potential of this microscope.”

Petrova’s first immigration hearing is scheduled for Tuesday. Her attorney, Gregory Romanovsky, said she was unfairly penalised. “For a first-time violation, the fine is typically reduced to $50. Instead, officials cancelled her J-1 scholar visa,” he said, calling her detention part of a broader effort “to create an unwelcoming and hostile environment for noncitizens.”
A Department of Homeland Security spokesperson said Petrova was “lawfully detained after lying to federal officers about carrying substances into the country.” Petrova refutes this, telling NBC News, “They asked if I have any biological samples in my luggage. I said yes.” She described days of isolation and confusion after her arrest.
Dr Leon Peshkin, Petrova’s supervisor and mentor at Harvard, said she is irreplaceable. “That was only her. It was only her,” he told NBC News. The lab’s work, which requires a rare combination of embryology and computational science skills, now hangs in the balance.
The case has caused concern among researchers nationwide, many of whom now fear travelling abroad or renewing visas. “I am horrified that it does,” Peshkin said, when asked whether immigration policies are discouraging international scientists from coming to the US.
According to Nature, 75% of surveyed scientists have considered relocating to Europe or Canada. Meanwhile, over 1,550 international students and recent graduates have had their visa status changed, and at least 28 lawsuits have been filed in US federal courts by students seeking to regain legal status.
Petrova, who came highly recommended after graduating from the prestigious Moscow Institute of Physics and Technology, was recruited to Harvard in 2021. “She’s a very talented scientist with huge potential … the capacity to be the best of the best,” said Rutgers molecular biologist Dr Konstantin Severinov.
Despite her detention, Petrova remains committed to her work. “I think this job was a miracle,” she said, adding that she won’t hide her political views. “If you want to say something against Putin, there is no way you won’t be in prison.”
Colleagues remain hopeful for her release, but fears persist. “We really don’t know if we’re ever going to see her again,” Trim said. “Because if they deport her to Russia, we may never see her again.”