Telangana forensic lab identifies Sigachi blast victims with rapid DNA analysis

Hyderabad: In the aftermath of the Sigachi factory explosion at Patancheru in Sangareddy district, the challenge of identifying the victims fell to the Telangana Forensic Science Laboratory (TGFSL). What arrived at the lab were fragments—some as small as two to three inches—collected from the blast site. These included skull shards, tissue remnants, and scorched bone matter. From this devastation, forensic experts were able to identify 26 victims, delivering the first set of DNA identification reports within 16 hours—an unprecedented pace in such cases. TGFSL has proven it can locate victims in mass disasters on par with global standards.

“There is a general perception among both officers and the public that DNA reports get delayed. This case proves otherwise. Despite severe challenges, we delivered DNA results within 16 hours,” said Shika Goel, the Director-General of TGFSL. The team worked through the night following the receipt of the samples on the afternoon of the blast. By 5 a.m. the next day, matches were confirmed using DNA fingerprinting. “Extraction of DNA was a big challenge,” the DG said. “Our young scientists worked relentlessly. We were also getting anxious calls from the SP, while families waited desperately.”

From the 77 samples received, five were found to be plastic materials mistakenly sent by police. Of the 72 viable human samples, 14 were entirely burnt and unusable for DNA extraction. From the remaining, 24 identifications were made quickly, and two more followed after extended analysis of human remains, bringing the total to 26. Eight victims, however, remain unidentified due to the absence of matching live samples or the complete destruction of biological material in the heat of the explosion.

Inside the lab

G Pandu, assistant director of the DNA division, detailed the scientific procedures used to retrieve usable genetic material. “We received various kinds of samples—tissue, broken bones, and partially burnt bones. The outer layers were removed, and reddish inner tissue was purified. Bone marrow and muscle tissue were also processed,” he said.

The laboratory used autosomal STR (Short Tandem Repeat) analysis to establish genetic profiles. In cases requiring paternal confirmation, Y-STR sequencing was applied, while mitochondrial DNA sequencing supported maternal lineage identification. Specialised equipment was used to expedite the decalcification process—a step that normally takes 10 to 15 days. Bone fragments were crushed into powder to allow faster extraction and decalcification, enabling the team to isolate DNA even from fragments measuring just a couple of inches.

Despite the challenges posed by severely degraded samples, the team’s methods proved effective. “Some of the samples were just 2 to 3 inches long—tiny fragments of skull bones—yet we could extract and identify DNA from them,” an official said.

Missing eight: Unidentified and unsettled

While 26 families have received clarity and closure, eight others are still waiting. These are the victims whose remains were either destroyed beyond recovery. Their status has implications beyond grief—compensation and legal formalities remain unresolved in the absence of formal identification.

The TGFSL has demonstrated its ability to function under extreme conditions and at scale. Handling approximately 2,000 DNA cases annually, with an average of five samples per case, the Telangana laboratory also processes cases from other states including Uttar Pradesh and Jharkhand, as well as referrals from the Central Forensic Science Laboratory.