With nearly all bodies charred beyond recognition after Thursday’s deadly crash of Air India flight AI171, authorities have turned to DNA testing to identify the 241 victims, as families await confirmation in anguish.
“It usually takes about 3 months to analyse an individual’s DNA and issue the report. We have expedited the entire process and will do it within 72 hours,” said Dr Saumil P. Merchant, professor and head, department of forensic medicine & toxicology, Narendra Modi medical college.
Speaking to Hindustan Times on Friday, he said the DNA tests would be conducted at forensic laboratories in Ahmedabad and Gandhinagar.
Merchant said a total of 275 samples have been collected from the remains of the deceased. “These include body parts disintegrated and kept in the mortuary,” he added. These body parts will be matched against DNA reference samples collected from relatives.
Harpreet Kaur Hora was among the 241 passengers who lost their lives in the crash. Her relative Rajendra Singh Hora said on Friday, “Her father's DNA test was done yesterday. He will be called after 72 hours.”
DNA testing in disasters follows a standard process. Rescue teams first recover human remains from the crash site, often in fragmented or burnt condition. These are sent to forensic labs for analysis.
Authorities reach out to victims’ families for DNA reference samples — from close relatives such as parents, children, or siblings. In some cases, personal items known to belong to the victim, such as a toothbrush, razor, or hairbrush, are collected for comparison.
The most common forensic method used is autosomal short tandem repeat (STR) profiling. This compares specific regions of DNA that vary greatly among individuals. If DNA from the remains matches that of a relative, or if statistical analysis supports a familial link, the remains can be identified.
In cases where only maternal relatives are available, mitochondrial DNA (mtDNA) analysis may be used. This type of DNA is inherited only from the mother and can help confirm identity when autosomal markers aren't sufficient.
In mass fatality events, statistical methods are crucial because remains from multiple individuals may get mixed. Analysts use likelihood ratios and Bayesian statistics to determine the strength of a match.
The accuracy of these tests improves when multiple relatives submit samples or when the remains yield strong, uncontaminated DNA.
Merchant said that the authorities are working to ensure that DNA tests are completed and results delivered within 72 hours of sample collection — an expedited timeline given the scale of the tragedy. “We have expedited the entire process,” he said, repeating the urgency of the effort.
The intensity of the crash has made other identification methods — such as fingerprints, dental records, or visual recognition — less reliable. In cases where DNA results are not conclusive or samples are degraded, authorities may combine multiple forms of identification, but DNA remains the backbone of the operation.