DNA double helix molecules and chromosomes.
Today’s Promega Connections blog is written by guest blogger Joliene Lindholm, Promega Technical Services Scientist.
In Promega Technical Services, we are frequently asked questions about choosing among our Human Genomic DNA products. Promega offers DNA that can serve as sources of normal human gene sequences or positive controls where genotype is not critical, and controls for use in genotyping applications like STR analysis. For mouse researchers, we also offer Mouse Genomic DNA. Continue reading
Promega will soon introduce the Spectrum CE System for forensic and paternity analysis. Building this system requires the efforts of many people from many disciplines—from our customers who have told us their needs to the engineers and scientists building the instrument and ensuring its performance. Periodically we will introduce our Promega Connections readers to a team member so that you can have a sneak peak and behind-the-scenes look at Spectrum CE System and the people who are creating it (of course if you truly want to be the first to know, sign up at www.promega.com/spectrum to receive regular, exclusive updates about Spectrum CE).
Today we introduce Jonelle Thompson, Validation Services Manager. Continue reading
While the forensic and general communities continue to argue about the merits of the recent Supreme Court ruling on collection of samples from arrestees prior to conviction, I am fascinated by the technology that make this question relevant. The conventional way of generating a DNA profile from a sample by STR (short tandem repeat) analysis is a long process involving a series of steps that require sophisticated expensive equipment, trained personnel and, more importantly, time. The actual process of DNA analysis consists of a) sample collection, b) DNA extraction, c) PCR amplification using 16 or more unique fluorescently labeled primer sets d) capillary electrophoresis to size labeled DNA amplicons, e) software analysis to size DNA fragments and allele calls based on migration of allelic ladder fragments, and f) comparison to known profiles in the database. This entire workflow can typically take days or even weeks, and therefore it is not surprising that we see newspaper reports of backlogs of criminal and other property cases. With these time ranges, the sample collected at a site would be of no practical use to most ongoing investigations. Continue reading
DNA testing methods are being used to solve problems in an ever-increasing number of fields. From crime scene analysis to tissue typing, from mammoths to Neanderthals, and from Thutmose I to Richard III, both modern mysteries and age-old secrets are being revealed. The availability of fast, accurate, and convenient DNA amplification and sequencing methods has made DNA analysis a viable option for many types of investigation. Now it is even being applied to solve such mundane mysteries as the precise ingredients used in a sausage recipe, and to answer that most difficult of questions “what exactly is in a doner kebab?” Continue reading
By now, you’ve seen the headlines. The bones that scientists found buried under a car park in Leicester, England, have been identified as those of the last Plantagenet king of England: Richard III. For those of you who might be new to this story, archaeologists identified and excavated the most likely burial spot for Richard III, under a car park near the Leicester City Council building, and unearthed a human skeleton with skeletal abnormalities similar to those of Richard III. Geneticists were called in to perform DNA analysis to determine if these bones were those of the English king. The DNA findings were just recently released. Now that scientists can say beyond a reasonable doubt that these bones belong to Richard III, we are learning new things about the ancient king. Continue reading
In July of 2009, the bodies of 43-year-old Alan Grna and his 85-year-old mother Julianna were discovered in their Ohio home—both victims of a violent assault. The lead detective in the case called in the Ohio Bureau of Criminal Identification and Investigation (BCI) to collect evidence from the crime scene, evidence that would lead them to the man who was eventually convicted of their murders. One of the key pieces of evidence was a roll of toilet paper.
Australian 53rd Battalion at Fromelles, 19 July 1916
On July 19, 1916, British and Australian forces launched a diversionary attack on heavily fortified German front lines near the tiny village of Fromelles in northern France to try to divert German resources from the Battle of the Somme, which was taking place only 50 miles to the south. Many men fell as they tried to cross the unfavorable ground between Allied trenches and the German fortifications. More than 5,500 Australian troops and 1,500 British soldiers were killed, wounded or captured during the two-day battle, making this Australia’s most costly battle of World War I. After Allied commanders refused a truce offered by the Germans to retrieve the fallen soldiers, the Germans recovered the bodies, loaded them onto a train, then transported them the short distance to Bois de Faisan, known as Pheasant Wood in English. Up to 400 of these bodies were buried there in five of eight hastily dug pits, then covered with the heavy clay soil and forgotten. These graves were lost to history until recently. Continue reading