Nepal floods: How DNA identification of bodies works

More than a week after a glacial collapse near the Langtang Lirung mountain peak set off devastating floods in Nepal and Tibet, sending a deluge of rocks, mud and water to the valleys below, forensic experts are working to identify bodies.

More than 1,270 people have been killed, and more than 4,700 are still missing, authorities said on Thursday . On Friday morning, reports emerged that two of the hundreds of workers trapped in tunnels at hydropower projects along the affected rivers had been rescued.

Meanwhile, authorities are using DNA testing to try to identify hundreds of bodies that have left morgues overflowing. Officials are urging first-degree relatives – fathers, mothers, sons, or daughters – of those reported missing to provide fresh blood samples for DNA profiling, police have said.

For missing foreign nationals, a first-degree relative (also a father, mother, son, or daughter) abroad can also undergo DNA profiling in their home country and email the results to Nepal Police for comparison. Hundreds of DNA samples have so far been collected from relatives.

The samples collected are being sent to the Nepal Police Forensic Science Laboratory and the Nepal Academy of Science and Technology.

So why is DNA identification important in the aftermath of the floods and how does it work?

In Nepal’s capital, Kathmandu, forensic teams are working to identify bodies – but many have been found in a state of decomposition, said Al Jazeera’s Jessica Washington, reporting from a DNA testing facility in the city.

“Forensic teams on the ground told us that there are some things that can help with the identification process, such as tattoos and jewellery, but many bodies were found in such a state that it is very challenging to identify them,” said Washington.