Identifying the criminals among multiple DNA samples

by gunshot and there were residual skin cells in the DNA sample mixed in with the blood.

Bioinformatics and computation biology

It can happen in any crime, and in one out of ten cases, says Darvasi, the evidence becomes inadmissible

 

Voskoboinik said that nothing can be done about it. He picked the right supervisor, however, because it was when he said that, that Darvasi came up with the plan.

That was a year ago or so,” he says. “And we developed a strategy to solve this problem. We proved the concept and theory mathematically. Strategically, we proved that we can identify the DNA with certainty in the presence or absence of certain markers.”

While it will take more replications and validation before it can be used in the court of law, Darvasi believes that it is just a matter of time. The invention that relies on looking at rare base pairs in DNA is now being commercialized by the university’s tech-transfer arm Yissum and “I have no doubt that it will be used in court,” the researcher states.

Israel21 reports that the new technology, expected to cost $100 to $200 per test, is a combination of bioinformatics and computation biology. The actual strategy was built on the basics of molecular biology using a lab on a chip.

It requires pinpointing the rare and unusual parts of a suspect’s DNA, rather than reading the DNA to test a mixture to see if the suspect is present or not.

A new tool for CSIs

Almost every cell in our bodies contains DNA. It is the genetic material that tells our cells how to work. Although 99.9 percent of human DNA is the same in each and every one of us, Darvasi is interested in the very minute parts of the 0.1 percent that are unique.

 

If all points of the rare DNA are in the suspect and the mixture as well, there is strong proof that the suspect was at the scene. To find the rare points, the team looks at all the rare variants that are spread throughout the entire genome and which are not linked one to the other.

The technique consists of investigating the DNA mixture and the suspect’s DNA for 1000-3000 single letter changes (polymorphisms), which are considered relatively rare in any population.

Current DNA fingerprinting methods look at only a few polymorphic sites to see if there is a match. Darvasi’s invention looks deeper into the sample to establish with a very high level of certainty whether or not a suspect’s DNA is in a mixture of up to ten people.

Looking at large numbers of base pairs, the team can show beyond a reasonable doubt whether or not the suspect was in the sample. Darvasi predicts that with the right investment, the technology could be developed into a product within a year.