A bone, a piece of muscle or a strand of hair -- these hold the key to providing a semblance of closure to the family of those who died, unknown and unclaimed in the Wayanad landslide in Kerala. 

Knowing this, the Kerala Government has initiated a complex, lengthy process of DNA profiling of samples collected from the mortal remains. Each body part is being sampled, numbered, preserved and sent for DNA analysis. The scale of this process and the complexities involved could be much bigger than the method undertaken during the Puttingal fire disaster and the Ockhi cyclone.

DNA analysis of 169 samples, which included intact bones taken from unidentifiable postmortem samples, partially burnt bone and flesh samples recovered from the site of the Puttingal temple firework disaster, helped identify 15 of the 17 missing persons in 2016. When cyclone Ockhi claimed lives in 2017, there were 74 bodies recovered from the sea, all in a decomposed state. Blood samples of 536 relatives were collected and the identities were revealed using DNA analysis, notes a report titled 'DNA Profiling for Mass Disaster Victim Identification' done by E V Soniya and Suresh Kumar U of Rajiv Gandhi Centre for Biotechnology (RGCB). 

The bodies being sampled in Wayanad arrive at the postmortem table, crushed, disfigured and dismembered. Intact samples are good sources of DNA. In decomposed bodies, sternum or femur bones (thigh bone) are used to build profiles. Often, swift collection of samples would prevent any kind of disintegration and it helps in obtaining complete profiles. It shows the importance of time taken from disaster to sample collection and analysis, notes the RGCB report. DNA profiles obtained from victim samples are compared to identify unique profiles and then these unique DNA profiles are compared with the DNA profiles of the relatives. As many as 96 samples can be loaded in one machine at a time, analysis of bone samples may take some time whereas a normal process could be done within 24 hours, an official said. 

DNA profiling is done using Short Tandem Repeat (STR) analysis, which establishes the identity of missing persons and confirms familial relations. STRs are short repeated sequences that make up approximately 3 per cent of the human genome. These sequences repeat a variable number of times in different individuals. A collection of these can give nearly irrefutable evidence statistically of a person's identity because the likelihood of two unrelated people having the same number of repeated sequences in these regions becomes increasingly small as more regions are analysed, according to an article published by the US Department of Justice. The identification process is always a challenge in open disasters like the one in Wayanad where the number or identity of victims involved is not known. In closed disasters like air crashes, victims are known making identification easier.

"It's a complex, but a very significant, humane task we have undertaken to honour the people who have lost their lives and their close ones. A unique identification number is created for each body following DNA sampling. This is then inserted in a plastic bottle which is enclosed in the grave along with the body. A small board is placed atop the grave carrying the same number. Once we obtain matches of DNA samples, survivors will know where their dear ones have been buried in the most honourable manner. Identification holds so much importance for the relatives. We had an instance where we were about to bury nine decomposed bodies the other day and just as we were ready, a family turned up and identified one of the bodies. We are making sure through DNA profiling that we establish identities for almost all the victims,'' said Minister for Revenue K Rajan. He said that a centralised system has been arranged at Kannur Forensic Laboratory to complete the process so that there is no disparity regarding technique or methods.

Till Tuesday, 148 bodies and 38 remains have been sampled and sent for DNA analysis at Meppadi. Two collection camps are running at Meppadi where blood samples are being collected from people in the relief camp and from those who have reported missing cases. "We are collecting teeth, sternum (chest bone) and muscles from bodies and are handed over to police. It is then sent to the regional forensic lab for analysis. We are collecting a minimum of two samples. In some cases, bodies may be dismembered and we try to get the clear, intact DNA to get the best possible matches," said Dr Dahar, who co-ordinates the sample collection process at Meppadi. A match will lead people to the exact spot where their family member lay buried, he said. 

Minister Rajan said that this is the reason why separate graves have been prepared even for a single body part and an identification number is displayed.

Identity is crucial in a disaster of this scale. It's not just about closure which is very important for the family, but there are also many other things which depend on this -- certificates, financial aid, compensation, insurance and other assistance in future for the family of the deceased, officials said. Samples are collected from those with direct relation -- father, mother, siblings, son or daughter and in some cases grandparents or grandchildren -- at two places at Meppadi. 

"We have completed the sample collection of relatives of those on the missing list. When relatives come to identify bodies and return after knowing that it is not their family member, we collect samples for analysis. We also collect the addresses of missing persons from them so that samples of immediate relatives can be collected," said Dr Binija Merin Joy who oversees the blood sample collection. 

"We have had instances of multiple claims for bodies. DNA profiles are made to give the family an opportunity to identify the deceased when there is no other way. It also gives them a closure which is very important in times of tragedies like these," said Tinku Biswal, Principal Secretary of the Disaster Management department.