A team of scientists developed a test that can estimate the age of an individual with only a blood sample. The method can be used, for example, forensic investigators who need information related to age of a suspect or dead.
The technique is based on the identification of a characteristic of a type of immune cells called T cells, which are transported in the blood.
These cells play a key role in the recognition of "invading" foreign to the body, such as bacteria, viruses, parasites or cancer cells.
As part of the process that cells use to recognize these invaders produce small circular DNA molecules.
The number of these molecules, known as excision circles of T cell receptor (sjTREC) decreases steadily with age.
According to scientists, the study shows that this biological phenomenon can be used to calculate "with precision and reliability," the age of a human individual. Strangers
This approach, say the researchers, will locate an individual in a category that extends generational in 20 years.
Predicting the "phenotypes" humans, the external characteristics of a person as hair and eye color-from the information in DNA is a new emerging field of forensic science.
But now, with the DNA information can be identified only a few features phenotypes with sufficient precision to have practical implications.
As explained by Dr. Manfred Kayser, who led the study, the new test has proved the most accurate of all tests that are designed to calculate a human characteristic phenotype from DNA information.
"The conventional DNA profiling to forensic science applied can only identify people who are already known to the investigating agencies," explains the scientist.
"Therefore, every forensic laboratory has found cases in which the DNA profile obtained from material evidence did not match any of the suspects tested no one in the database of criminal DNA.
"In those cases, it is expected that the information is clear evidence of material help find strangers," he adds.
Experts expect the new test, along with the methods currently used to reconstruct the appearance of strangers from a biological sample found at the scene of the crime, eventually help to solve more cases.
The details of the investigation carried out in Medical Center of Erasmus University in Holland, are published in the journal Current Biology. (BBC)
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