DNA sequencing challenge for Odisha train crash victims

BHUBANESWAR: The agony of the kin of train crash victims is far from over. As the bodies stored in five containers at AIIMS-Bhubaneswar have started decomposing making it difficult for the relatives to identify them, more challenging times are ahead for DNA sequencing and matching.

Since the bodies were received more than 30 hours, some of them 48 hours after death, it will be a herculean task for the forensic labs to conduct DNA sequencing and profiling with the quality of samples. Sources said samples like molar teeth, muscle tissue, bone and hair have been collected from 123 bodies received by AIIMS while the claimant relatives have provided their blood samples for matching.

Although a molar tooth is an ideal sample for extraction of quality DNA, in some cases, doctors involved in autopsy had to store canine or incisors teeth in case of unavailability of molar teeth besides muscle tissue, blood gauze and hair samples. Bones were collected from the body parts like legs or hands received from the accident spot.

Bodies can be preserved for years only if embalming is done properly within 12 hours and an adequate amount of DNA can be extracted if the sampling is done within the period. DNA sequencing of bodies in an advanced state of decomposing is often a problem, particularly if the ideal body remains like molar teeth are not available or muscle tissue quality is bad.

AIIMS started receiving bodies from Balasore after 3.20 am on June 4, nearly 32 hours after the train crash. While the health facility had received 123 bodies that day, 39 more were received on June 7 after their autopsy at Capital Hospital.

The health authorities were yet to get details on the DNA samples collected there. Embalming also got delayed as AIIMS has the capacity for only 30 bodies. All the bodies were preserved after containers from Paradip Port arrived here a day later.

“Though all precautions have been taken while collecting samples, DNA sequencing will be a challenging task. Profiling will take time, but not difficult,” AIIMS superintendent Dr DK Parida said.

DNA samples of 123 bodies and 29 samples from claimants have been sent to AIIMS Delhi. As the case has been handed over to CBI, the sequencing will be done at the CFSL labs at Delhi and some other locations like Chandigarh. Since 82 bodies are still unidentified, DNA profiling of these bodies will be conducted first along with the samples of claimants for matching.

The complete process will take at least two to three weeks considering the number of samples.