Breakthrough in Burn Victim Identification: Ancient DNA Tech Offers New Hope
by Jo Ellen Nott
A recent study by Binghamton University researchers offers hope for identifying victims of fires where traditional methods fail. Fire victims can be identified through dental records if the teeth are preserved and such records exist. DNA testing is often the only way to identify badly burned bodies.
The key challenge of DNA testing under these circumstances is determining the amount of degradation the DNA suffers after exposure to high temperatures. Previously, usable DNA could only be extracted from remains exposed to temperatures below 250 degrees Celsius. Binghamton anthropologist Matthew Emery’s research utilizes techniques originally developed for extracting DNA from ancient specimens like woolly mammoths to potentially identify badly burned human remains.
Emery’s team used two DNA extraction techniques: one designed for ancient DNA and another commonly used in forensics. The second, the total demineralization protocol, was created by Odile Loreille, a forensic scientist with the FBI and one of the paper’s co-authors. The team’s findings confirm an inverse relationship between fire temperature and DNA preservation. In other words, “the higher the burn temperature, the less DNA is preserved.”
Both techniques yielded positive results for remains burned below 350 degrees Celsius.
However, the ancient DNA method proved superior for extracting shorter DNA fragments, making it more effective for victims exposed to temperatures above 350 degrees Celsius.
The research also established a method for estimating fire temperatures based on bone discoloration patterns. Bones burned at temperatures below 200 degrees Celsius are typically well-preserved, while yellow and brown discoloration evidences fire temperatures between 200 and 300 degrees, and a black or smoked appearance is produced by burn temps between 300 and 350 degrees. Bones subjected to temperatures between 550 and 600 degrees Celsius may appear gray, and temperatures above that lead to a white or scorched appearance.
This information allows forensic investigators to prioritize bones most likely to yield usable DNA. Long bones, like the femur and tibia, are prime targets due to their dense structure, which offers better DNA protection.
The results of the Binghamton University study have significant implications for solving cold cases where fire was involved. Emery is now collaborating with Arizona’s Maricopa County to identify victims from unsolved cases in which previous technology lacked the sensitivity to extract usable DNA.
The study shows the potential of repurposing existing techniques from a seemingly unrelated field like paleontology to advance forensic science.
Sources: Forensic, Science Daily
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