Polymerase Chain Reaction (PCR) Analysis PCR analysis is a technique that allows technicians to create millions of precise DNA replications from a single sample of DNA. In fact, DNA amplification alongside PCR can let forensic scientists perform DNA analysis on samples that are as tiny as only a couple of skin cells. In contrast to some other DNA analysis techniques, PCR analysis has the advantage of analysing minuscule sample sizes, even if they are degraded although they must not be contaminated with DNA from other sources during the collection, storage and transport of the sample.
Contents contributed and discussions participated by Kareena M
Forensic News Blog - 3 views
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In 2012, readers searching for forensic science content now have many more ways to find
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"The body chemistry of the person who left the fingerprint can tell us some things," said Shaler. "If the suspect is older or younger or a lactating mother, for example."The researchers used a form of physical vapor deposition -- a method that uses a vacuum and allows vaporized materials to condense on a surface creating a thin film. Normally, the deposition process requires exceptionally clean surfaces because any speck of dust or grease on the coated surface shows up as a deformity. However, with fingerprints, the point is to have the surface material's ridges and valleys -- topography -- show up on the new surface so analysts can read them using an optical device without the necessity of chemical development or microscopy."This approach allows us to look at the topography better and to look at the chemistry later," said Shaler. "We wouldn't have thought of this by ourselves, but we could do it together."One benefit of this approach would be the ability to retrieve fingerprints off fragments from incendiary or explosive devices and still be able to analyze the chemicals used in the device.The specific method used is a conformal-evaporated-film-by-rotation technique developed to create highly accurate copies of biological templates such as insect eyes or butterfly wings. Both are surfaces that have nanoscale variations."It is a very simple process," said Lakhtakia. "And fingerprints are not nanoscale objects, so the conformal coating is applied to something big by nanotechnology standards."
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Investigators have found new DNA evidence in the murder of Peggy Hettrick, a case that was considered closed until genetic evidence freed a man who spent 10 years in prison, according to Colorado Attorney General John Suthers.The "touch DNA" tests weren't available in the late 1990s. Timothy Masters was convicted of murder in Hettrick's death in 1999, but his conviction was overturned in 2008 after defense lawyers used advanced DNA testing to uncover evidence suggesting a different suspect.The new evidence was taken from Hettrick's clothing. "We have done 'touch DNA,' and I think it has moved the ball forward. We will know more in the future," Suthers said. He wouldn't say whose DNA was found or identify the clothing on which it was found.Masters has not been exonerated in the case and remains a suspect."While we are not in a position to exonerate Tim at this time, I emphasize that he is presumed innocent and is no more a suspect than a variety of other people," Suthers said.
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BBC News - DNA crime-fighting in UK 'lagging behind', experts say - 0 views
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Cross-border co-operation on terrorism and crime will be compromised unless the UK updates the technology it uses for DNA profiling, experts have warned.
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Using EU recommended markers Not using recommended markers Dat
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Experts also say that the "chemistry" that underlies DNA testing kits used by UK forensic science labs is now more than a decade old and that newer, more sensitive systems can obtain results from even low quality samples - improving success rates. Some argue that such information can potentially make or break a case.
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Forensic DNA - 1 views
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