How DNA water test can determine fate of missing people
A NEW form of DNA analysis has been developed in Derby that can determine whether a missing person has drowned in a river or lake.
Techniques developed to detect great-crested newts in water have been re-applied by forensic science firm SureScreen Diagnostics to assist in the search of a body.
By taking a swab from the missing person’s toothbrush, experts can test whether their DNA is present in a watercourse.
The method can help find bodies faster, saving police forces time and money.
Tom Wood, biology laboratory manager at SureScreen, said: “This could revolutionise the way missing persons are tackled.
“The average human has around 37 trillion cells, and each one of them carries the DNA which uniquely identifies that person. Just one cell or the DNA released from it in water would be enough to carry out our test.
“It is of great value, whether the result is positive or negative, because even a negative will put the family’s mind at rest and will allow police to put their resources to best use elsewhere.”
Searching for a missing person is hugely expensive. Every year, around 327,000 people are reported missing in the UK and each case costs the police £2,415 on average.
Agata Stodolna, who developed the sampling methods at SureScreen, said the new process could bring that cost down considerably.
She said: “It’s been a challenge developing the process, but now we are confident that if a body is present, we would find it.
“We just need a sample of DNA from the missing person’s toothbrush, or a cheek-swab DNA match from a next-of-kin to compare with DNA extracted from the water by the special processes we have developed.
“We’ve used ourselves as guinea pigs, dispersing our own DNA in our own ponds at Morley, then searching for it again later.”
Mr Wood said the new form of analysis could be relied upon and that even a body in a car boot would be detected.
He said: “The analysis is so elegant. We don’t get false positives, because even if that person swam in the water previously, the DNA they left behind is only stable for a month. The person has to be there, emitting DNA into the water all the time for us to detect a positive.
“It is incredibly sensitive, too. We can find one part in a million million, so a body in a lake shouldn’t present a problem to us, even if it was a child or baby.
“In time, we hope to be able to quantify the amount of DNA from several positions in a big lake or river to help police target where the body lies when results are positive.
“The work is very exacting. It requires precision sampling, careful extraction and the latest analytical methods.”
Mr Wood said the trials of the new form of DNA analysis had been “very encouraging” and that the next stage is to become involved in a real incident to demonstrate the accuracy of the technique.
He said: “We would be delighted to get involved with police forces faced with searching for a missing person, as that is the only way we can verify in practice what we have proven in principle.”
SureScreen has facilities at Chester Green, in Derby, and at Morley, and was winner of the Derby Telegraph Business Awards for innovation in 2014, and runners-up in 2015.