Police can now tell identical twins apart – just melt their DNA

newscientist.com ^ | Jessica Hamzelou

[BenLurkin]

Graham Williams at the University of Huddersfield, UK, has a different way – to look for modifications to the twins' DNA that have come about as a result of their lifestyles.

Such epigenetic changes occur when a chemical group known as a methyl group attaches to a gene and modifies the way it is expressed. This happens as a body is influenced by a person's environment, lifestyle and disease.

Williams's team took mouth swabs from five pairs of twins. After extracting the DNA from each sample, the group used a chemical to target parts of the DNA that did not have methyl groups attached, and change the number of hydrogen bonds at these points. Any difference in the number of hydrogen bonds should change the melting point of a compound.

When the team heated up the twins' DNA samples, they found the melting points were different – allowing them to tell the twins apart genetically. The test was also much quicker than whole genome sequencing, says Williams. "It can be done in just a few hours."

[Alex Murphy]

When the team heated up the twins' DNA samples, they found the melting points were different – allowing them to tell the twins apart genetically. The test was also much quicker than whole genome sequencing, says Williams. "It can be done in just a few hours."

"Build a man a fire, and he will be warm for a night.
Set the man on fire, and he will be warm for the rest of his life."