DENVER - DNA evidence will almost certainly play a pivotal role in the ongoing investigation into the murder of Jessica Ridgeway, but a noted DNA expert cautions it can also potentially lead investigators down a rabbit hole.

Take the backpack that was found shortly after Jessica Ridgeway was reported missing as an example. It was found in a neighborhood in Superior.

"What if some kid sneezed on [Jessica's] backpack during recess [at her school]? Then we're focusing all of our efforts on this, and when we don't find that person we then think we haven't found the killer," Dr. Elizabeth Johnson told 9News from her California home on Monday.

Dr. Johnson has more than 20 years of experience working in the field of DNA technology. She was called by the defense to testify during the Kobe Bryant case in Colorado. She currently works in private forensic consultation.

"I think the biggest misconception about DNA technology is that it is infallible and that there are never mistakes made," she said. "Just because you someone's DNA on an object doesn't make them guilty of a criminal act."

Of course, she said, the presence of particular bodily fluids can also be indicative of a criminal act, and thus lead investigators closer to a killer. But she cautions that CSI-like television shows have raised the expectations of many people in inappropriate ways.

Dr. Andrew Bonham is a professor at Metropolitan State University and says he still believes DNA will help in the Ridgeway murder investigation.

"I am almost 100 percent convinced," the molecular biology expert said. "That (the killer) is going to leave traces of DNA behind and that investigators are going to find those traces."

He said that current technology allows investigators to collect even seemingly miniscule portions of bodily fluids in an effort to identify critical DNA markers.

"We're now talking about almost less than you can perceive," he said.

Go here to read the rest:
DNA will play pivotal role in Ridgeway case

The Irish Times - Monday, October 15, 2012

PETER CLUSKEY in The Hague

DUTCH police have carried out the biggest DNA sweep in the history of the Netherlands, taking samples from more than 6,500 men in 12 separate villages, in a renewed attempt to solve the countrys most infamous murder that of 16-year-old schoolgirl Marianne Vaatstra, in 1999.

The DNA sampling was completed on Thursday, and police said at the weekend that they had successfully collected samples from 89 per cent of the 7,300 men still living within a five-mile radius of the meadow where Vaatstras body was dumped 14 years ago.

The schoolgirls age and the particularly gruesome nature of the murder she was raped, strangled and had her throat cut caused revulsion in the Netherlands. As a result there have been repeated attempts over the years to find her killer, most recently in 2007 using 3D technology.

The department of justice has refused on a number of occasions to give permission for such a wide sweep, but in June it relented on the grounds that DNA testing has become much more sophisticated and that police say they may have some of the killers DNA, which was discovered at the scene.

Hopes of a breakthrough now centre on a Playboy cigarette lighter found in the grass near the victims body in the field in Veenklooster, in the northern province of Friesland.

DNA found on the lighter, which was bought in a local shop, matches DNA found on the dead girls body and police hope it may still lead them to someone closely related to the killer.

One of the most controversial aspects of this murder case in 1999 was that, because the body was found near a centre for asylum seekers, the focus of the investigation and of local anger rapidly became the refugees.

An Iraqi who had recently left the camp was detained in the UK, while an Afghan was detained in Turkey. Both voluntarily gave DNA samples and were ruled out.

More:
New DNA hunt for killer of Dutch schoolgirl

THE owner of Argentina's powerful Clarin media group wants kidnapping charges dropped after DNA tests failed to link her adopted children to those stolen during the country's 1976-1983 "dirty war," her newspaper has reported.

The request, filed on Friday, comes after DNA samples submitted by the two adult children of Ernestina Herrera de Noble showed no matches with a DNA data bank of relatives of those who disappeared during the dictatorship.

Some 30,000 people vanished during the military's war on leftist activists.

The Grandmothers of the Plaza de Mayo, which represents female relatives of dictatorship-era victims, alleges that some 500 babies were stolen from those who disappeared - and then were adopted by pro-junta families.

Of those, only 107 have been identified.

The kidnapping case against Herrera de Noble was originally filed in 2001, and, after years of legal manoeuvering, a court ordered Marcela and Felipe Noble Herrera to submit to the DNA testing.

"There is no more cross-checking to do," attorney Gabriel Cavallo told the daily Clarin.

The case should be closed because "the experts have already determined that neither Felipe nor Marcela are the children of people who disappeared during the dictatorship," Mr Cavallo said.

But the Grandmothers of the Plaza de Mayo were not ready to admit defeat.

The group has long suspected the Noble Herrera children, both born in 1976, were kidnapped. It says the data bank is being still being updated because many people did not know that their daughters or daughters-in-law were pregnant at the time they vanished.

Link:
DNA 'clears magnate of kidnapping'

12 October 2012 Last updated at 12:42 ET

A legal challenge to the retention of DNA samples by police in Northern Ireland could have repercussions across Europe, Belfast High Court has heard.

The test case has been brought by convicted drink driver Fergus Gaughran.

His lawyers argued DNA profiles and fingerprints of those found guilty of lesser offences should not be retained.

They want a European ruling which found it was unlawful to hold samples from people arrested but later acquitted to be extended to cases like Gaughran's.

Our case is that the collection of this information and the indefinite retention on the police computer systems is unlawful

Newry-based solicitor Paul Fitzsimons predicted potentially huge consequences if the judicial review challenge succeeds.

He said: "If there is a judgment upholding our client's position it could lead to the destruction of vast amounts of police records built up in Northern Ireland, the United Kingdom and throughout Europe."

Mr Fitzsimons issued legal proceedings on behalf of Gaughran, who was stopped at a police checkpoint in Camlough, County Armagh three years ago.

Gaughran failed a breath test and was subsequently convicted and disqualified from driving for a year.

Originally posted here:
Challenge to European DNA records

The DNA of Idelfonso Velez was discovered on the kitchen knife authorities say was used to stab Trisha Bennett and Angel Ortiz to death in 2010.

Velez, 29, of Framingham, is on trial in Middlesex Superior Court on two counts of first-degree murder in the deaths of Bennett and Ortiz, who were found stabbed to death inside their Hudson apartment in May 2010.

Andrea Borchardt-Gardner, a senior DNA analyst with Bode Technology in Virginia, told jurors Thursday she tested several DNA samples from the handle, tip and the recasso, the portion of the knife where the handle meets the blade. She found the samples matched Velezs DNA.

The probability of a randomly selected, unrelated person matching the DNA from the profile on the handle, tip and recasso is 1 in 2.8 quintillion, said Borchardt-Gardner.

The current world population is estimated to be about 7 billion, said Borchardt-Gardner.

"I can say to a reasonable degree of scientific certainty that Mr. Velez is the source of that DNA profile," said Borchardt-Gardner.

Borchardt-Gardner also testified Thursday that Bennetts DNA was found on the recasso portion of the knife. The probability of a randomly selected, unrelated person matching Bennetts DNA from the recasso section of the knife is 1 in 3.1 trillion.

Earlier this week, Massachusetts State Police Trooper Kevin Murphy said Velez told him that he entered Ortiz and Bennetts bedroom the night of the murders after hearing Bennett scream "baby, baby, baby."

Velez told Murphy that a man with a knife was standing over Ortiz and then attacked him before dropping the knife as he was running from the apartment. Velez then picked up the knife for his safety and placed it in the kitchen sink, said Murphy.

Alanna Frederick, a chemist with the Massachusetts State Police, also told jurors that DNA tested from a swab of blood spatter on the left thigh of the jeans Velez wore the night of the murders matched the DNA of both Velez and Bennett.

See more here:
Prosecution: Velez' DNA found on knife used in Hudson murders

Scientists have finally found out how long DNA lasts in fossils. Alas, their discovery puts dreams of real life Jurassic Parks to rest for good.

[More from Mashable: Liquid Nitrogen + Ping Pong Balls = Crazy Science Fun]

As it turns out, DNA has a half-life of 521 years, according to researchers who studied fossils of extinct giant birds found in New Zealand. Previously, nobody knew exactly how long DNA lasted before decaying, which meant that technically it was possible to extract and read DNA from ancient fossils. A theory which was the premise of the movie Jurassic Park and which allegedly prompted a billionaire to try cloning a dinosaur.

[More from Mashable: Sound Waves Make Liquids Levitate, Develop Better Drugs [VIDEO]]

This confirms the widely held suspicion that claims of DNA from dinosaurs and ancient insects trapped in amber are incorrect, said Simon Ho, a computational evolutionary biologist at the University of Sydney in Australia. Sorry, Jurassic Park fans, you're never going to see a breathing Tyrannosaurus rex.

To find out more about why one of our childhood dreams has been just a delusion, and about this important scientific discovery check out the video above.

This story originally published on Mashable here.

Link:
DNA Half Life Discovery Rules Out Real Life Jurassic Parks [VIDEO]

They're called discreet DNA samples, and the Elk Grove, California, genetic-testing company easyDNA says it can handle many kinds, from toothpicks to tampons.

Blood stains from bandages and tampons? Ship them in a paper envelope for paternity, ancestry or health testing. EasyDNA also welcomes cigarette butts (two to four), dental floss ("do not touch the floss with your fingers"), razor clippings, gum, toothpicks, licked stamps and used tissues if the more standard cheek swab or tube of saliva isn't obtainable.

If the availability of such services seems like an invitation to mischief or worse - imagine a discarded tissue from a prospective employee being tested to determine whether she's at risk for an expensive disease, for instance - the Presidential Commission for the Study of Bioethical Issues agrees.

On Thursday it released a report on privacy concerns triggered by the advent of whole genome sequencing, determining someone's complete DNA make-up. Although sequencing "holds enormous promise for human health and medicine," commission chairwoman Amy Gutmann told reporters on Wednesday, there is a "potential for misuse of this very personal data."

"In many states someone can pick up your discarded coffee cup and send it for (DNA) testing," said Gutmann, who is the president of the University of Pennsylvania.

"It's not a fantasy to think about how, without baseline privacy protection, people could use this in a way that would be really detrimental," such as by denying someone with a gene that raises their risk of Alzheimer's disease long-term care insurance, or to jack up life insurance premiums for someone with an elevated genetic risk of a deadly cancer that strikes people in middle age.

"Those who are willing to share some of the most intimate information about themselves for the sake of medical progress should be assured appropriate confidentiality, for example, about any discovered genetic variations that link to increased likelihood of certain diseases, such as Alzheimer's, diabetes, heart disease and schizophrenia," Gutmann said.

The commission took on the issue because whole genome sequencing is poised to become part of mainstream medical care, especially by personalizing medical treatments based on a patient's DNA.

$1,000 genome

That has been driven in large part by dramatic cost reductions, from $2.5 billion per genome in the Human Genome Project of the 1990s and early 2000s to $1,000 soon. Several companies, including Illumina Inc. and Life Technology's Ion Torrent division, sell machines that can sequence a genome for a few hundred dollars, but that does not include the analysis to figure out what the string of 3 billion DNA "letters" means.

Read the original post:
US panel urges end to secret DNA testing over privacy concerns

A man was arrested Wednesday after he was linked through DNA to the sexual assault of an 8-year-old Santa Ana girl in her bunk bed, police said. The assailant climbed in through an unlocked window of her home.

Damien Anthony Reyes was arrested at his home in the 1300 block of North King Street after detectives were told there was a positive match on the DNA left at the scene of the June attack.

Reyes was booked at the Santa Ana Jail on suspicion of burglary, child molestation by force with enhancements that could lead to a potential life sentence upon conviction. He is being held in lieu of $1 million bail.

Authorities did not say how Reyes' DNA got into the state or federal DNA database. In most cases an arrest or conviction leads to a DNA sample being taken.

The noise woke up the girl's 13-year-old sister, who was asleep on the bottom bed, police said. Both girls screamed and woke up their father, who ran to their aid.

Detectives said the man immediately fled the house through the same window and was last seen running south.

Man found with body bags, smoke grenade at LAX investigated

Hazing probe launched after Fresno State fraternity pledge dies

-- Richard Winton

Originally posted here:
DNA leads to arrest in sexual assault of Santa Ana girl

A new analysis confirms the widely held suspicion that DNA from dinosaurs and ancient insects trapped in amber cannot be recovered to make a 'Jurassic Park'-style theme park

By Matt Kaplan and Nature magazine

Palaeogeneticist Morten Allentoft used the bones of extinct moa birds to calculate the half-life of DNA. Image: M. Mhl

Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...

Read More

From Nature magazine

Few researchers have given credence to claims that samples of dinosaur DNA have survived to the present day, but no one knew just how long it would take for genetic material to fall apart. Now, a study of fossils found in New Zealand is laying the matter to rest and putting paid to hopes of cloning a Tyrannosaurus rex.

After cell death, enzymes start to break down the bonds between the nucleotides that form the backbone of DNA, and micro-organisms speed the decay. In the long run, however, reactions with water are thought to be responsible for most bond degradation. Groundwater is almost ubiquitous, so DNA in buried bone samples should, in theory, degrade at a set rate.

Determining that rate has been difficult because it is rare to find large sets of DNA-containing fossils with which to make meaningful comparisons. To make matters worse, variable environmental conditions such as temperature, degree of microbial attack and oxygenation alter the speed of the decay process.

But palaeogeneticists led by Morten Allentoft at the University of Copenhagen and Michael Bunce at Murdoch University in Perth, Australia, examined 158 DNA-containing leg bones belonging to three species of extinct giant birds called moa. The bones, which were between 600 and 8,000 years old, had been recovered from three sites within 5 kilometres of each other, with nearly identical preservation conditions including a temperature of 13.1 C. The findings are published today in Proceedings of the Royal Society B.

See the original post here:
Dinos' DNA Demise: Genetic Material Has a 521-Year Half-Life

In "Jurassic Park," scientists extract 80-million-year-old dino DNA from the bellies of mosquitoes trapped in amber. Researchers may never be able to extract genetic material that old and bring a T. rex back to life, but a new study suggests DNA can survive in fossils longer than previously believed.

The oldest DNA samples ever recovered are from insects and plants in ice cores in Greenland up to 800,000 years old. But researchers had not been able to determine the oldest possible DNA they could get from the fossil record because DNA's rate of decay had remained a mystery.

Now scientists in Australia report they've been able to estimate this rate based on a comparison of DNA from 158 fossilized leg bones from three species of the moa, an extinct group of flightless birds that once lived in New Zealand. The bones date between 600 and 8,000 years old and importantly all come from the same region.

Science news from NBCNews.com

Although Einstein's theories suggest nothing can move faster than the speed of light, two scientists have extended his equations to show what would happen if faster-than-light travel were possible.

Temperatures, oxygenation and other environmental factors make it difficult to detect a basic rate of degradation, researcher Mike Bunce, from Murdoch University's Ancient DNA lab in Perth, explained in a statement.

"The moa bones however have allowed us to study the comparative DNA degradation because they come from different ages from a region where they have all experienced the same environmental conditions," Bunce said.

Based on this study, Bunce and his team put DNA's half-life at 521 years, meaning half of the DNA bonds would be broken down 521 years after death, and half of the remaining bonds would be decayed another 521 years after that, and so on. This rate is 400 times slower than simulation experiments predicted, the researchers said, and it would mean that under ideal conditions, all the DNA bonds would be completely destroyed in bone after about 6.8 million years.

"If the decay rate is accurate then we predict that DNA fragments of sufficient length will preserve in frozen fossil bone of around one million years in age," Bunce said.

But he cautioned that more research is needed to examine the other variables in the breakdown of DNA.

View post:
How long can DNA last? A million years

BOCA RATON, FL--(Marketwire - Oct 10, 2012) - DNA Brands, Inc. ( OTCBB : DNAX ), makers of the great tasting DNA Energy Drink, a favorite of the action sports community and its enthusiastic followers, announced today it is re-branding its entire line of DNA Energy Drinks to be able to reach a greater portion of the ever-growing energy drink market.

Darren Marks, President of DNA Brand, Inc., stated, "The one comment we hear over and over is that energy drinks don't taste good. We were previously selected as the best tasting energy drink by an independent international World Beverage Competition. We intend to get this fact out to the energy drink consumer. Our current graphics were primarily geared to the action sports community. Although we will continue to pursue these same customers, we will do it with new and innovative products geared to better communicate the brand's core identity while appealing to a much broader demographic; active consumers from every walk of life. We are confident that this rebranding will enable us to better position ourselves in a category that continues to re-invent itself and grow at a rapid pace. Energy drink sales increased 17.2% in 2011, the highest growth rate since 2007." In conjunction with the re-branding, Jeff Jonke has been promoted to the Company's Executive Vice-President and General Manger. He will be the driving force behind this new and exciting time for DNA Brands, Inc.

About DNA Brands, Inc.

DNA BRANDS, makers of DNA Energy Drink, the award-winning, best-tasting energy drink at the 2010 World Beverage Competition, is a proprietary blend of quality ingredients in four flavors: Citrus, Lemon Lime, Sugar Free Citrus and CRANRAZBERRY. DNA can be found at independent retailers throughout the state of Florida, as well as national retailers including Walgreens, Race Trac and Circle K. Distribution is primarily through Grass Roots Beverage, the Company's wholly owned subsidiary and select Miller and Anheuser-Bush distributors in select markets.

DNA is a proud sponsor of many action sport teams. True to its action sports roots, DNA BRANDS, INC. has earned national recognition through its sponsorship of the DNA Energy Drink/Jeff Ward Racing team where it competes on a world-class level in Supercross and Motocross, reaching millions of fans. DNA Energy Drink can also be found in other action sports such as Surfing, BMX, Wakeboarding and Skateboarding and its athletes are recognized stars in their own right.

For more information about DNA Energy Drink, its athletes and sponsorships, please visit http://www.dnabrandsusa.com or contact: Darren M. Marks, President (954) 970 3826 darren@dnaenergydrink.com

Safe Harbor Forward-Looking Statements

To the extent that statements in this press release are not strictly historical, including statements as to revenue projections, business strategy, outlook, objectives, future milestones, plans, intentions, goals, future financial conditions, future collaboration agreements, the success of the Company's development, events conditioned on stockholder or other approval, or otherwise as to future events, such statements are forward-looking, and are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. The forward-looking statements contained in this release are subject to certain risks and uncertainties that could cause actual results to differ materially from the statements made.

See the original post here:
DNA Brands to Re-Brand and Undertake New Marketing Campaign

In "Jurassic Park," scientists extract 80-million-year-old dino DNA from the bellies of mosquitoes trapped in amber. Researchers may never be able to extract genetic material that old and bring a T. rex back to life, but a new study suggests DNA can survive in fossils longer than previously believed.

The oldest DNA samples ever recovered are from insects and plants in ice cores in Greenland up to 800,000 years old. But researchers had not been able to determine the oldest possible DNA they could get from the fossil record because DNA's rate of decay had remained a mystery.

Now scientists in Australia report they've been able to estimate this rate based on a comparison of DNA from 158 fossilized leg bones from three species of the moa, an extinct group of flightless birds that once lived in New Zealand. The bones date between 600 and 8,000 years old and importantly all come from the same region.

Temperatures, oxygenation and other environmental factors make it difficult to detect a basic rate of degradation, researcher Mike Bunce, from Murdoch University's Ancient DNA lab in Perth, explained in a statement.

"The moa bones however have allowed us to study the comparative DNA degradation because they come from different ages from a region where they have all experienced the same environmental conditions," Bunce said.

Based on this study, Bunce and his team put DNA's half-life at 521 years, meaning half of the DNA bonds would be broken down 521 years after death, and half of the remaining bonds would be decayed another 521 years after that, and so on. This rate is 400 times slower than simulation experiments predicted, the researchers said, and it would mean that under ideal conditions, all the DNA bonds would be completely destroyed in bone after about 6.8 million years.

"If the decay rate is accurate then we predict that DNA fragments of sufficient length will preserve in frozen fossil bone of around one million years in age," Bunce said.

But he cautioned that more research is needed to examine the other variables in the breakdown of DNA.

"Other factors that impact on DNA preservation include storage time following excavation, soil chemistry and even the time of year when the animal died," Bunce said in a statement. "We hope to refine predictions of DNA survival by more accurately mapping how DNA fragments decay across the globe."

The study was published Oct. 10 in the journal Proceedings of the Royal Society B.

Read the original here:
'Jurassic Park' May Be Impossible, But Dino DNA Lasts Longer Than Thought

Researchers in New Zealand found that DNA decays far quicker than previously considered, making it impossible to salvage usable genetic material from dinosaurs.

Don't worry, we won't have to worry about this scenario in the future.

Countless childhood dreams dissolved today upon the news that the calculated half-life of DNA figures out to around 521 years, all but invalidating the chances of a real-life "Jurassic Park."

The DNA fact-finding project involved a team of palaeogeneticists testing 158 leg bones belonging to three species of extinct giant moa birds ranging from 600 to 8,000 years old.

After running a series of comparisons between the age of the various bones and DNA degradation within each specimen, the researchers estimated that DNA's half-life works out to about 521 years after being kept in a swamp with an average temperature of 13.1 Celsius (55 Fahrenheit). Even a more ideal preservation temperature of minus 5 Celsius (23 Fahrenheit) would only result in readable DNA from specimens up to 1.5 million years old, meaning there is no possible way we can see a 65-million-year-old T-Rex waving its tiny arms about in this time frame.

DNA breaks down for a variety of reasons, including degradation from external influences such as temperature, water, soil chemistry, and so on. After half a millennium, the researchers assume that DNA continues to degrade as the nucleotide bonds within break in half. Each 521-year segment serves as another chapter of nucleotide structure breakdown and carries on until the bonds no longer exist. However, science has yet to determine the breakdown speed of DNA in environments that are more supportive of preservation, such as permafrost.

Morten Allentoft at the University of Copenhagen and Michael Bunce at Murdoch University in Perth, Australia, worked with a large team on the findings, which were published today in the Proceedings of the Royal Society B science journal.

(Via Nature)

Read the rest here:
DNA decay rate makes 'Jurassic Park' impossible

10 October 2012 Last updated at 12:37 ET

DNA representing a one-in-a-billion match to that of a retired teacher and the man accused of her murder was found on her hand, a court has heard.

A "full DNA profile" of Stephen Farrow, 48, was found on a swab taken from the back of Betty Yates's left hand following the discovery of her body.

Farrow denies the murders of Mrs Yates, in Worcestershire, and the Rev John Suddards, in South Gloucestershire.

He claims he saw 77-year-old Mrs Yates two days before she was killed.

She was found stabbed to death in her cottage, in Bewdley, on 4 January, having been killed two days earlier.

Farrow, of no fixed address, claims he saw Mrs Yates on 30 December, but Bristol Crown Court heard the location the DNA sample was found would make it "extremely rare" to get such a strong profile days later.

Forensic scientist Christopher McKenzie told the jury: "The DNA profile obtained showed a mixture of DNA from two people which matched the corresponding DNA profiles of Mrs Yates and Stephen Farrow.

"We found that it is a billion times more likely to have come from Betty Yates and Stephen Farrow than from Betty Yates and someone other than Stephen Farrow."

Mr McKenzie said given the strength of the DNA profile he would expect there to have been either direct physical contact between Mrs Yates and Farrow or for it to have come from a bodily fluid - potentially saliva or sweat.

View post:
Murder accused's DNA 'on victim'

HAPPIER TIMES: Lloyd and Corryn Rayney on a family holiday in Canada in late 2003-early 2004. Source: PerthNow

A DNA expert based in London was called in to investigate whether Lloyd Rayney or another, unidentified "person of interest" were involved in the 2007 death of Mr Rayney's estranged wife, Supreme Court registrar Corryn Rayney.

But tests by forensic scientist Rosalyn Treliving did not shed any light on who may have been responsible for Mrs Rayney's death.

Ms Treliving, who specialises in the analysis of body fluids and the interpretation of DNA profiles, was asked by Major Crime Squad officers to examine hairs, DNA extracts and a handkerchief collected from crime scenes related to the case.

In a written statement tendered to the Supreme Court in Perth, she said her DNA tests were to "assist in addressing the issue" of whether Mr Rayney or a second person - whose name has been withheld - were involved in Mrs Rayney's death on August 7, 2007.

She said she understood Mr Rayney and the second individual were both "persons of interest" in the investigation.

The prominent Perth barrister has been on trial for three months charged with wilfully murdering his wife at the family home in Como on the night of August 7, 2007.

Prosecutors have alleged that Mr Rayney killed Mrs Rayney at their home before placing her body in the back of her State-issued car and driving to Kings Park where he buried her in a clandestine bush grave.

He has pleaded not guilty.

Ms Treliving said she examined hair and DNA extracts from Mrs Rayney's car; hair samples from outside the Rayneys' Como home; a handkerchief found in Mrs Rayney's grave; DNA from a tree branch near the gravesite and DNA extracts from hairs found at the grave, on Mrs Rayney's clothing and in the body bag in which she was placed after being removed from the grave.

Read the rest here:
UK DNA expert drew a blank with tests

ScienceDaily (Oct. 9, 2012) Many diseases, including cancers, leave genetic clues in the body just as criminals leave DNA at the scene of a crime. But tools to detect the DNA-like sickness clues known as miRNAs, tend to be slow and expensive. Now a chemist and a biologist from University of Copenhagen have invented a method that promises to shave days off the lab work done to reveal diseases, using cheap methods and easy to use analytical apparatuses.

Chemistry researcher Tom Vosch and plant molecular biologist Seong Wook Yang invented a DNA sensor, coupling genetic material to a luminous molecule which goes dark only in the presence of a specific target. Details on their invention, Silver Nano cluster DNA-probes, are published in the high profile scientific journal ACS Nano, and Tom Vosch is understandably proud of the invention.

"We invented a probe that emits light only as long as the sample is clean. That is an unusually elegant and easy way to screen for a particular genetic target," says Vosch of the Department of Chemistry's Nano Science Centre.

DNA clues help detect disease

You could say that the inventors took their cue from crime detection. In murder cases police technicians use DNA to identify the killer. Similarly Individuals with disease are likely to have a unique miRNA profile. Any disease that is attacking a patient leaves this genetic clue all over the victim. And because the profiles of miRNAs vary by type of cancer, finding it proves beyond a reasonable doubt what made the patient sick.

Gene magnets stick to opposites

The new detection method exploits a natural quality of genetic material. A single DNA strand is made up of molecules, so called bases, ordered in a unique combination. When two strands join to form their famous double helix, they do so by sticking to complementary copies of themselves. Likewise strands tailored to match particular miRNAs will stick to the real thing with uncanny precision. But detecting this union of the strands was only made possible when Vosch and Yang paired their skills.

A real kill switch

Tom Vosch is specialized in studying molecules that light up. Seong Wook Yang is specialized in miRNA. Together they figured out how to attach the light emitting molecules to DNA sensors for miRNA detection. Vosch and Yang discovered, that when these luminous DNA-strands stick with microRNA-strands, their light is snuffed out, giving a very visible indication that the target miRNA is present in the sample. In other words: When the light goes out, the killer is in the house.

Likely to lead to high speed cancer diagnostics

Read this article:
Glowing DNA invention points towards high speed disease detection

A new study is finally laying to rest the debate over whether DNA from the age of the dinosaurs could survive to the present day.

Scientists at Murdoch University led a study which shows the rate of DNA degradation and calculates that all bonds in a DNA strand preserved at the ideal temperature of minus five degrees centigrade would be completely destroyed in bone after approximately 6.8 million years.

This figure is incompatible with the idea of finding intact DNA in an 80 million year old dinosaur remnant, as was famously alluded to in the Steven Spielberg film Jurassic Park, but is much older than the currently accepted record of 450,000 to 800,000-year-old DNA from Greenlandic ice cores.

Dr Mike Bunce and Dr Morten Allentoft from Murdoch Universitys Ancient DNA lab came to their conclusions after studying 158 fossilised leg bones belonging to three species of the moa, an extinct group of birds that once roamed New Zealand.

It has been agonisingly difficult to estimate the rate of DNA decay before now because finding a large set of DNA-containing fossils with which to make meaningful comparisons are exceedingly rare, said Dr Bunce.

Environmental conditions like temperature, degree of microbial attack and oxygenation, can affect the DNA decay process and make it hard to detect a basic rate of degradation.

The moa bones however have allowed us to study the comparative DNA degradation because they come from different ages from a region where they have all experienced the same environmental conditions.

The fossil bone specimens were carbon dated as being between 600 and 8000 years old and looking at the varying degrees of DNA degradation in each specimen, the team were able to calculate a DNA half-life of 521 years. The half-life is the amount of time taken for an amount of DNA to reach 50 per cent of the starting amount.

The scientists found that the estimated decay rate in the specimens was almost 400 times slower than predicted from simulation experiments carried out in the lab.

Based on these calculations and other investigations, the team were able to make their predictions of DNA survival deeper into time.

Read more:
Mystery of DNA decay unravelled

ST. LOUIS Rodney Lincoln has spent half his life in prison and knows he will spend the rest there, too, unless a sealed Federal Express container en route to Lorton, Va., can unlock his cell.

Inside: A swab of red stain from the front edge of a kitchen sink. A piece of aluminum door frame with a bloody fingerprint. A steak knife and butcher knife, both with blood. A broom. And a piece of tissue paper left near a doorway where the killer fled.

Those are among the physical evidence stored for decades from the gruesome murder of JoAnn Tate and attack on her two young daughters at their St. Louis apartment on April 27, 1982.

Now, with the state's blessing, the evidence will be tested by Bode Technology, in the suburbs of Washington. It specializes in DNA comparisons, science not available at the time of the crime.

The Midwest Innocence Project is paying for the testing, believing the results will not only free Lincoln whose case they've been fighting for years but also point to a particular man it suspects of being the real killer.

Tate's family, however, hopes the tests will put a final stamp on Lincoln's conviction and provide closure.

A GRUESOME CRIME

Police who responded on that spring morning to Tate's apartment on Farrar Street encountered a gory scene.

Tate, 35, was facedown in a pool of blood, fatally stabbed in the chest and sexually assaulted with a broom. The killer delivered 10 stab wounds to Tate's daughter, Melissa, 7, and sliced the throat of Renee, 4.

Melissa feebly told relatives who found them, "Bill did it."

Read the original:
DNA testing keeps convicted killer's hopes alive

Palaeogeneticist Morten Allentoft used the bones of extinct moa birds to calculate the half-life of DNA.

M. Mhl

Few researchers have given credence to claims that samples of dinosaur DNA have survived to the present day, but no one knew just how long it would take for genetic material to fall apart. Now, a study of fossils found in New Zealand is laying the matter to rest and putting paid to hopes of cloning a Tyrannosaurus rex.

After cell death, enzymes start to break down the bonds between the nucleotides that form the backbone of DNA, and micro-organisms speed the decay. In the long run, however, reactions with water are thought to be responsible for most bond degradation. Groundwater is almost ubiquitous, so DNA in buried bone samples should, in theory, degrade at a set rate.

Determining that rate has been difficult because it is rare to find large sets of DNA-containing fossils with which to make meaningful comparisons. To make matters worse, variable environmental conditions such as temperature, degree of microbial attack and oxygenation alter the speed of the decay process.

But palaeogeneticists led by Morten Allentoft at the University of Copenhagen and Michael Bunce at Murdoch University in Perth, Australia, examined 158 DNA-containing leg bones belonging to three species of extinct giant birds called moa. The bones, which were between 600 and 8,000 years old, had been recovered from three sites within 5 kilometres of each other, with nearly identical preservation conditions including a temperature of 13.1 C. The findings are published today in Proceedings of the Royal Society B1.

By comparing the specimens' ages and degrees of DNA degradation, the researchers calculated that DNA has a half-life of 521 years. That means that after 521 years, half of the bonds between nucleotides in the backbone of a sample would have broken; after another 521 years half of the remaining bonds would have gone; and so on.

The team predicts that even in a bone at an ideal preservation temperature of 5 C, effectively every bond would be destroyed after a maximum of 6.8 million years. The DNA would cease to be readable much earlier perhaps after roughly 1.5 million years, when the remaining strands would be too short to give meaningful information.

This confirms the widely held suspicion that claims of DNA from dinosaurs and ancient insects trapped in amber are incorrect, says Simon Ho, a computational evolutionary biologist at the University of Sydney in Australia. However, although 6.8 million years is nowhere near the age of a dinosaur bone which would be at least 65 million years old We might be able to break the record for the oldest authentic DNA sequence, which currently stands at about half a million years, says Ho.

The calculations in the latest study were quite straightforward, but many questions remain.

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DNA has a 521-year half-life

We are used to radioactive substances having a half-life, but DNA? Now a study of bones from extinct birds suggests the double helix too has a measurable half-life and that we have underestimated its ability to survive in the fossil record.

"DNA degrades at a certain rate, and it therefore makes sense to talk about a half-life," says Morten Allentoft at Copenhagen University, Denmark, who together with Mike Bunce at Murdoch University in Perth, Australia, and colleagues, extracted DNA from the leg bones of 158 extinct flightless birds called moas.

Part of the reason a DNA half-life has been so elusive is that it is hard to find a large enough cache of samples that have been exposed to similar conditions. The moa bones were all between 600 and 8000 years old, and came from a 5-kilometre-wide area of New Zealand's South Island, key factors for helping identify a regular pattern of decay.

With an estimated burial temperature of 13 C, the DNA's half-life was 521 years almost 400 times longer than expected from lab experiments at similar temperatures, says Allentoft.

The oldest DNA to date belongs to insects and plants and was found in 450,000 to 800,000-year-old ice. Under subzero conditions, Allentoft and Bunce estimate that DNA's half-life can be up to 158,000 years, meaning the last remnants would disappear around the 6.8-million-year mark. Allentoft does say that is an optimistic assessment, and doesn't imply that samples of DNA large enough to measure could be extracted from such old bones.

Eva-Maria Geigl at the Jacques Monod institute in Paris, France, is still to be convinced by the half-life claims, which she says rest on statistically weak evidence. She points out, for example, that the correlation relies heavily on the moa bones older than 6000 years when fewer than 10 of the 158 bones are this ancient.

"Old fossils are rare and hence there will be less data in this part of the analysis," says Bunce. "There is nothing we can do about it other than present what we have at hand and clearly, the signal is present. The correlation is highly significant."

If DNA decays in a predictable way, can we calculate the chances of finding it at key sites? Ever since the Indonesian island of Flores yielded remains of the "hobbit", Homo floresiensis in 2004, speculation has been rife that some specimens might contain DNA that would help pin down its position in the human family tree. This notion has been spurred by evidence that the hobbits may have survived until as recently as 18,000 years ago.

Unfortunately, Bunce thinks the new calculations will be difficult to apply to specific sites. "A host of other factors come into play," he says, including the season the organism died. In fact, although the moa bones in the analysis had been buried in a similar environment, the age of the specimens could account for only about 40 per cent of the variation in DNA preservation in other words, the half-life signal is noisy.

Alan Cooper, director of the Australian Centre for Ancient DNA at the University of Adelaide, South Australia, agrees. "The rotting process after death is very seasonal and context dependent, and has a major impact on DNA survival."

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DNA's half-life identified using fossil bones