DNA Fingerprinting: Science Steps In To Help Identify Air Crash Victims

As the nation mourns the victims of the devastating Air India crash in Ahmedabad, science is quietly stepping in to offer solace to grieving families. In a special NDTV interview, one of India's foremost molecular biologists, Dr Rakesh Mishra, former Director of the Centre for Cellular and Molecular Biology (CCMB), Hyderabad, and currently Director, Tata Institute for Genetics and Society, Bengaluru explained how DNA fingerprinting can play a pivotal role in identifying victims - even when bodies are severely charred.

What is DNA Fingerprinting?

DNA fingerprinting, Dr Mishra explained, is a well-established technique used to identify individuals based on their unique genetic code. "From any biological material-be it tissue, blood, saliva, or even a hair follicle - we can extract DNA," he said. "Even a very small amount is sufficient."

The process involves isolating DNA and analyzing specific regions of the genome known as short tandem repeats (STRs). These regions vary significantly among individuals, making each person's DNA profile unique. "We can determine whether two samples come from the same individual or different individuals, and even establish familial relationships," he added.

Can It Work in a Plane Crash?

One of the most pressing questions in the aftermath of the Air India plane crash is whether DNA can be extracted from bodies that have been severely burned. Dr Mishra was unequivocal: "Yes, it's possible. DNA is present in almost every cell of the body, and even if the tissue is charred, we can often retrieve it from bones or small fragments."

He pointed out that forensic scientists have successfully extracted DNA from ancient remains, including Neanderthals. "If we can do that, we can certainly identify victims from a recent crash," he said.

Speed and Accuracy

In emergency situations, time is of the essence. According to Dr Mishra, DNA fingerprinting can be completed in as little as a day if fast-tracked. "DNA isolation takes a couple of hours, and the rest of the analysis can be done within a few more. Under standard conditions, it usually takes a couple of days," he said.

The accuracy of the method is also beyond question. "Each person has a unique DNA signature. While we can't tell the name of the person from the DNA alone, we can confirm their identity by comparing it with samples from relatives," he explained.

India's Capability and Infrastructure

India is well-equipped to handle such forensic challenges. "We have our own technology," said Dr Mishra. "Thanks to pioneers like Dr Lalji Singh, former director of CCMB and a pioneer in DNA fingerprinting, India was among the first countries to accept DNA evidence in courts."

The Centre for DNA Fingerprinting and Diagnostics (CDFD) in Hyderabad is the national hub for such work. Additionally, state-level labs like the Gujarat Biotechnology Research Centre (GBRC) in Gandhinagar are also capable of collecting and processing DNA samples. "These are now fairly standard techniques," he said. "Even local police are trained in how to collect and preserve biological samples."

Handling Mixed Samples

In mass casualty events like plane crashes, remains are often commingled, raising concerns about whether individual identities can still be determined. Dr Mishra acknowledged the complexity but remained optimistic. "If blood from two people is mixed, it becomes tricky. But if tissues are collected separately, we can distinguish between individuals," he said.

He emphasized the importance of careful sample collection. "Tissues should be placed in separate polythene bags and transported on ice to a certified lab. This ensures the integrity of the samples," he added.

The Science Behind the Process

The core of DNA fingerprinting lies in the polymerase chain reaction (PCR), a technique that amplifies specific DNA regions. "We look at multiple markers-sometimes 50 or more. If 40 match between two samples, it suggests a familial relationship. If none match, they are un-related," said Dr Mishra.

This allows scientists to not only identify individuals but also establish relationships-such as confirming whether two victims were siblings or parent and child. "It's a powerful tool for bringing closure to families," he said.

A Message of Hope

There is a role of science in times of tragedy, the victims' families can be assured that identification is possible, even in such dire circumstances.

Dr Mishra said, "Science can go where other technologies fail. DNA fingerprinting is one such example. It's unfortunate that we need it in such situations, but it's reassuring to know that we have the tools to help, and India has its own indigenous technology."