Posts Tagged ‘dna’


What is a human chimera?

Wed, Oct 28th, 2015

Human chimera: What the rare condition is, and why there might be many more people with it than we realised.

This article was first published online by The Independent (UK) on 27 October 2015.

Doctors are finding more and more instances of human chimeras — a condition that might affect far more people than we realise.

Human chimerism hit the headlines this week after it was revealed that a man had failed a paternity test because he had the condition — which meant that the genetic father of his child was his unborn twin.

The condition occurs when one unborn child absorbs the cells of another miscarried sibling in the womb, leading to the surviving person taking some of the genes of their “ghost” twin. That can lead to strange results in the DNA of people that have the condition — but it can often go completely unnoticed.

The condition is relatively common in some animals — but it may happen more often than we realise in humans, and go unnoticed. And it may become yet more common, as more people use fertility treatments to conceive their children.

In previous cases, people have been found to have two different blood types, or to develop different sexual organs from those that would be associated with the rest of their body.

Another example involved Karen Keegan, a woman from Boston in the US who had a different set of genes in her blood cells and her ovaries. Her children were not genetically hers — and the real genetic mother was a twin sister that was never born.

In the case of the Washington man reported this week, different genes were found in his cheek — where the saliva in the test was taken from — and his sperm. That meant that he was excluded from a paternity test, but a DNA-based ancestry check showed that he was the child’s uncle.

But many people who have the condition will never take a paternity test for their children, or find out through other means. That is likely to mean that many people could have the condition, and never know.

Studies have suggested that the condition might be present in 21 per cent of triplets, and eight per cent of twins. But many of those people would never know — because testing is likely to show up the result, unless it is being searched for.

Chimerism might already be far more common than we realise, but it could become even more prevalent, Barry Starr, a geneticist at Stanford. Fertility treatments are much more likely to lead to multiple births, and so are in turn far more likely to produce more people with chimerism.

A version of the condition called “artificial chimerism” can also occur through transfused blood stem cells — though that is less common because transfused blood now tends to be hit with radiation to help the host absorb it — or through bone marrow transplantation.

DNA Detective Prof Valerie Corfield explaining DNA technology

Wed, Sep 16th, 2015

Our very own and the original ‘DNA Detective’ Prof Valerie Corfield explains how applications of DNA technology are used to solve crimes in the following video created by the Public Understanding of Biotechnology (PUB) as part of a series on basic biotechnology.

Specialist police sniffer dogs lead to 215 arrests

Mon, Jun 29th, 2015

As long as crime has been fought, dogs have been used in the battle to keep lawlessness at bay. But mention a police dog and thoughts inevitably turn to that of a dog with its teeth bared, chasing down a criminal or keeping angry protesters at bay during riot control.

However, there is an elite group of 30 dogs in South Africa that never bare their teeth, and are usually friendly Border Collies or Labradors.

These are the dogs known as the biological, body fluid detection canines. They are specialised in detecting blood and semen. It is this ability that helps detectives solve crimes or gather vital evidence, especially in murder and rape cases.

National police spokesperson Brigadier Vishnu Naidoo said in the year ended March 2015, these specialist canines were involved in almost 2 300 searches with 706 samples of blood or semen found and 215 suspects arrested.

There is one such dog at the Umzinto Dog Unit on the KwaZulu-Natal south coast. Paris loves nothing more than to chase down a tennis ball and bring it back to her handler, Warrant Officer Jason Reddy. However, the moment he puts her harness on, it is time to work seeking out blood or semen that is not readily visible.

K9 unit

What kind of dog is recruited to help the detectives?

“It has to be a dog with a friendly disposition. It also needs to be a dog that can get into small areas,” says Reddy, a 20-year veteran of the police. At least 18 of those years have been with the police dogs, or the K9 unit, as it is more commonly known.

Border Collies, Labradors and on occasion German Shepherd dogs are used. Paris is a black and white Border Collie with a little more than five years of service and, according to Reddy, has been the crucial link in a number of cases that have resulted in convictions.

In one case in which two girls were raped in Hibberdene on the KwaZulu-Natal south coast, Paris found a drop of blood that was not seen by the naked eye. The sample was taken and tested. The DNA from that small drop matched the DNA of a suspect already on the police’s database.

“That suspect had a previous conviction and we had his DNA on our database. He got 25 years,” said Reddy.

Paris has been trained to differentiate between human and animal samples. She can smell a pinprick-size sample of blood that is not visible to the human eye and can smell blood even if it has been washed away.

In a case where three people were killed in a hit-and-run accident, it was Paris’s sharp smelling ability that picked up the trace of blood inside a hole that would normally contain a screw holding the mud flap of the car that clinched the case. The driver, whom police suspected, had washed the car. The blood found by Paris was tested and found to belong to one of the three dead girls. Her sharp nose saw to it that the driver was convicted of culpable homicide.


The dogs like Paris are picked once they are at least 14 months old and then undergo training at the police’s K9 Dog Training Academy in Roodeplaat in Pretoria.

Captain Cliffie Pillay, who is responsible for the police’s canines in KwaZulu-Natal, said the handlers of biological, body fluid detection canines must have had at least two years of experience as a dog handler.

Reddy was previously the handler of a dog trained to seek out explosives. And before he was teamed up with Paris, he too had to undergo training.

Reddy and Paris get called out once a day by detectives for murder cases or by the Family, Violence, Child Protection and Sexual Offences Unit for rape cases.

In fact it was such a dog that was called out to help police last week in the hunt for two men who are alleged to have raped an American tourist in the Tsitsikamma National Park.

In one case where a couple was arrested for stabbing Umzinto grandmother Sushila Pillay, Paris located the alleged murder weapon – a knife – in the Umzinto River a week after the murder.

In Durban’s western suburb of Malvern, police had caught the suspect who had told them where he had thrown the knife used to stab a man. Officers could not find it in the open patch of land, but Paris found it still with the victim’s blood on it. While not necessary for the conviction, it solidified the case the police had against the man.

99% success rate

A quiet “Soek” from Reddy sends Paris looking for blood or semen, depending on what is required. When she finds it, she sits down at the spot. And that is when the forensics experts move in to confirm her good work and extract samples required for DNA testing.

In another case a woman who was raped repeatedly in a forest in Dududu near Umzinto was so distraught that she could not recall where in the forest the crime had occurred.

Reddy and Paris were called in and five different crime scenes in the forest were located by Paris.

Paris is expected to work for another five years at least, but even she is tested annually by Pillay to ensure that she is up to scratch.

According to Pillay, Paris will find that sample of blood or semen more than 99% of the time.

There are currently only two biological, body fluid detection canines working in KwaZulu-Natal, but according to Pillay there are plans to bring more of dogs like Paris to KwaZulu-Natal, so criminals beware.

This article was first published by on 21 June 2015

CSI: Reality vs Fiction

Mon, Aug 22nd, 2011

CSIWe have all seen some form of those crime television programs, whether it’s CSI, NCIS or some other program with an arm length acronym. They all seem to follow the same cookie cut scenarios: a crime is committed, the overly good looking CSI guys arrive and collect the smallest traces of physical evidence which no human would be able to find without super-vision. Then they race back to their state of the art labs where they instantly identify exactly who committed the crime, rush off to arrest the suspects and deliver a clever line about how could they think they would get away with the crime. Although these shows are extremely interesting and most of the techniques are accurate, the time frame is often enormously exaggerated. For example, in my lab we enjoyed watching this clip from CSI where what took them 60 seconds, would take us an entire day, not to say we were lazy and took our time, if they were to show the entire process it would be extremely boring and the show would lose all suspense.

Horatio CaineSo although CSI is based on accurate information, it is largely a fictional program. It would be illogical to have someone like Horatio Caine working on a case from beginning to end, if the criminals knew who is working with a sample which could alter the verdict of their sentence, they would try their upmost to influence or threaten that person.  So in reality, the forensic analyst works with anonymous samples so there is no bias or chance of influencing the results.

Another interesting byproduct of these shows is a new psychological effect, called the ‘CSI effect’ named after the original crime scene program but all of these crime scene programs adds to the effect.

You would think this ‘CSI effect’ would not have any real world ramifications, however, the effects are being felt in America courtrooms where they use a panel of their peers to decide the verdict of a criminal case. During jury selections, potential jurors are now being asked whether they are avid watchers of CSI related TV shows as these people may have unrealistic expectations in certain cases. They expect to have some form of DNA or physical evidence linking the criminal to the crime scene everytime and without it they are less likely to find the defendant guilty, as well as they jury have a higher conviction rate if DNA evidence is available. With jurors heard to complain that “they didn’t even dust for fingerprints on the lawn”, the level of unrealistic expectations has increased.

A paper was published in the journal, National Institute of Justice, where they looked at this CSI effect. The survey indicated jurors that, 46 % they expected some kind of scientific evidence in every criminal case, 22% expected some kind of DNA evidence, 36 % expected fingerprint evidence, and 32% expected some kind of ballistic or firearm lab evidence. However, contrary to the expectations of the study, jurors were more likely to find a defendant guilty than not guilty even without scientific evidence if the victim or other witnesses testified, except in the case of rape. So although crime scene TV shows caused jurors to have higher expectations for scientific evidence than there non-watching counterparts, these expectations had little effect on the jurors propensity to convict.

Although there is anecdotal evidence that this ‘CSI Effect’ which has increased the layman’s knowledge of these scientific practices exists, there does not seem to be any real world influence, at least in the case of jurors.

Anyone who watches these programs will say they are extremely interesting, whether they are skeptical or believe every part of the show is a different story.  In South Africa where crime seems to be a pastime, it is sweet respite to be able to watch these guys on TV find and arrest criminals using physical evidence, whether its ballistics or DNA evidence, hoping that these techniques are being used to catch our criminals here.


This week’s blog entry was written and compiled by Grant Godsmark, a Genetic Hons student who works with The DNA Project and conducts DNA Awareness Training in the KZN Region. Read more about Grant here

Grant Godsmark

Grant Godsmark

Groundbreaking New Training Program Developed

Mon, Aug 15th, 2011
DNA Project team

DNA Project Team

Members of the DNA Project gathered together in Cape Town last month for the 2nd Annual DNA Project’s Trainers Workshop. The objective of this year’s workshop was to critically assess the DNA Awareness Campaign we have been running for the past year to identify whether any changes or improvements needed to be made to the programme, based on the field experience of our Trainers who have been hosting workshops throughout South Africa.

The second and more exciting reason for the gathering was to ‘brainstorm’ around the development of the innovative new ‘Train the Trainer’ program which the DNA Project wants to initiate as phase two of its DNA Awareness Campaign.

Currently, the way in which we have been disseminating DNA Awareness to the private security sector, guarding services, emergency services, community police forums, the justice system and general public, has been through directly contacting these sectors of the community and offering to host free DNA Awareness workshops at their respective premises.  We believe, however, that a more effective approach to ensure DNA Awareness training would be to introduce DNA Awareness training at Trainer level, which enables those organisations which conduct their own training to provide ongoing DNA Awareness training at their premises at their own convenience. We believe that by including DNA Awareness training as part of their basic crime scene management training, it will ensure that they are comprehensively taught about the value of crime scene preservation. In addition, no matter what the turnover of staff is within a company, each new employee will automatically receive DNA Awareness training at entry level. By creating DNA Awareness as an industry standard, these  sectors of the community will be able to offer this as an added value service to their existing protocols.

In other words, instead of ‘fishing’ for the community we would like to teach these sectors  how to ‘fish for themselves’.

How will a Train the Trainer workshop differ from our basic DNA Awareness Workshop we currently offer?

The Train the Trainer workshop will consist of a full day’s training, whereby an instructor from the DNA Project will impart the basics of the science behind DNA forensics and crime scene preservation. These Train the Trainer workshops, as with the DNA Awareness workshops, will be sponsored by the DNA Project and thus will be free of charge.

Course Outline

  • A simple summary of DNA, the techniques of DNA profiling and the benefits of a National DNA Criminal Intelligence Database in crime investigation.
  • The responsibilities of the First Officer attending the crime scene with potential DNA evidence will be covered.
  • The Trainers will be taught how to identify the potential sources, locations and limitations of DNA evidence so that they can pass on this valuable information to Trainees during crime scene training.
  • An overview of the correct handling and packaging of samples from crime scenes, suspects and complainants and who should be doing what.
  • Trainees will be provided with information relating to the legislation that regulates the use of DNA as an evidential tool.
  • The Trainees will briefed as to what actually happens in a South African Forensic Lab  and how much of “CSI” is fact and what is fiction.
  • The central message of our DNA Awareness Campaign will be covered, and the reasons why these six steps are so important will be explored , namely:








For more information, or if you interested in attending a Train the Trainer workshop or DNA Awareness workshop, please contact Maya Moodley at the DNA Project on or tel (021) 418 0647.

Women’s ‘Arrest Law’: Warning

Sun, Jul 24th, 2011

Recently, we received the email below:


An incident took place – a young girl was attacked by a man posing as a plain clothes officer; he asked her to come to the police station when she & her male friend didn’t have a driver’s license to show. He sent the male friend off to get his license and asked the girl to accompany him to the police station. Instead he took her to an isolated area where the rape was committed.

The law [which most of us are not aware of] clearly states that between 6 pm and 6 am, a woman has the right to REFUSE to go to the Police Station, even if an arrest warrant has been issued against her.

It is procedural that a woman can only be arrested between 6am and 6pm, unless she is arrested by a woman officer and taken to an ALL WOMEN police station. If she is arrested by a male officer, it has to be proven that a

woman officer was on duty at the time of arrest.

Please fwd this to as many girls/women you know. Guys, protect your wives, sisters and mothers by knowing this law. It is good for us to know our rights.

Do not neglect, fwd to your entire buddy list.


After some research, we identified that this email is a hoax which has been circulating the internet for a few years and has been credited in various forms in different countries throughout the world. Although a law such as this would be great in terms of our high rate of rape in South Africa, it is simply not true.

One thing which females should remember if they are arrested, is that under the Criminal Procedures Act, a woman can only be searched by a female police officer. This is your right and if this is not performed by a female you have the right to insist that it is.

If you come across any emails such as this, please do not forward this incorrect information further. Although your intentions are noble, by passing on these hoax emails, you could inadvertently cause someone to be charged with refusing arrest, if they believe that these emails are true.

Dr. Carolyn Hancock on 702 Radio

Wed, Jun 29th, 2011

Last Sunday, Udo Carelse from 702 Radio invited Dr. Carolyn Hancock to discuss the DNA Project and the role of DNA forensics in South Africa. 702 Radio has a special slot on a Sunday morning where they address issues of crime. They get station commanders from various policing stations to address issues in their areas. However, this week’s focus was on the recent break-ins at both the Gauteng police commissioner Mzwandile Petros’s home and the former national commissioner Jackie Selebi’s home. The general view was that such high profile people definitely receive special attention when they are victims of crime. However, changing to a slightly different

Udo Carelse

issue, Udo chatted to Carolyn about what is being done for the average South African when DNA evidence is left at a crime scene. They also discussed the new DNA Bill and the study tour currently being undertaken by the parliamentary committee to Canada and the UK. Below is the sound clip of the interview with Carolyn where she highlights the roll of DNA forensics and the need for the expansion of South Africa’s national DNA database. Please remember to contact us at if you are interested in our DNA awareness workshops!

Click on the link below for the interview, or right click and save the file.

Dr Carolyn Hancock 702 Radio

Note: The legislation was drafted in 2008 and not 1998 as stated in the sound clip.

Is DNA forensics being used in South Africa?

Mon, Jun 27th, 2011

Yes! DNA is used in a number of forensic investigations that are performed daily in South Africa. This is great news but unfortunately this amazing technology is still under utilised in our country. So what has been in the news lately?

A single cigarette butt left at the scene of a robbery and murder has led to the conviction of a 24-year-old man

An article, published in ioL news on the 21st June, describes how DNA evidence was used to convict a 24-year old man of the robbery and murder of Cornelia Janneke. Without the DNA evidence collected by police and the CSI team, Thumelo Monakedi would have never been brought to justice. The accused vehemently denied ever being at the scene of the crime. However, the saliva on the tip of a cigarette butt irrefutably proved his presence at the crime. With a 23 billion chance of the DNA profile on the cigarette not being the accused, it shows without any doubt who committed this crime!

With one child going missing every six hours in South Africa I found another recent article very interesting. A pilot project that involves the collection of pupil’s fingerprints, saliva swabs, hair samples and a photo ID of the pupil, has been introduced into a school in Brackenfell on the 20 June 2011.

OUCH! Bastion Primary Grade 1 pupil Anita Steyn, 7, braces herself as Sjean de Kock, a fourth-year social work student, takes a hair sample to be included in the IDENT-A-KID database, aimed at keeping children safe. Picture: Jeffrey Abrahams

Note is also taken of physical features, such as hair and eye colour as well as age. All this information will be stored on a school database, so that if a missing child is found the police will be able to identify the child. With projects like this in South Africa, we would also be able to identify missing children and reunite them with their families.

So going back to the main question, is DNA being used in forensic investigations in South Africa? Yes it is – but there is SO much more that still needs to be done….. For example, we desperately need to pass the amendment to the Criminal Procedures Act which would allow for the expansion of our National DNA Database. Unfortunately, due to the this legislation not being considered by the Parliamentary Committee for Police, the police are not empowered to utilise DNA evidence to it’s full potential. To quote a recent article written by Chris Asplen on the delay in the legislation regarding the expansion and regulation of the national DNA database, “hundreds of thousands of children’s lives are sacrificed because of the failure to act by politicians in South Africa.”