2017 finds Promega on the road visiting cities all across the United States. This year we are presenting workshops from leaders in the forensics community on topics like maximizing success with challenging samples, improving laboratory efficiency and reducing backlogs, and new tools and technologies for the forensics laboratory. This highly popular workshop series is a great way to learn from your peers about new techniques and workflows and network with other forensics experts in your region.
Today’s Promega Connections blog is written by guest blogger Rachel H. Oefelein, QA Manager/Senior DNA Analyst at DNA Labs International.
Shakespeare said, “The evil that men do lives after them; the good is oft interred with their bones.” This is continually true in the case of unidentified remains throughout the United States. The action of a person going missing or the events leading to an individual’s demise are frequently the memory that haunts a town or the media for years to come. However, for each such case, somewhere lies a set of skeletal remains not yet found, or just as tragic, recovered but still unidentified. The National Missing and Unidentified Persons System (NamUs) estimates approximately 40,000 sets of unidentified skeletal remains linger in morgues around the country or that have been cremated and buried as Jane and John Does.
Many crime labs do not have protocols in place for the extraction of DNA from skeletal remains or have outdated protocols for bone extraction that are not sensitive enough for poor quality bones. Bones are often recovered from harsh environments and have been exposed to extreme heat, time, acidic soil, swamp, chemicals treatment, etc. These harsh environmental conditions degrade the DNA present in the remains which further complicates the already difficult procedure of releasing the DNA in cells buried deep within the bone matrix. Another challenge is that cases often involve recovery of skeletal remains in areas with animal activity, water recoveries and scenes involving explosions or fires; these case types may require re-association of dozens if not hundreds of bones and bone fragments. Continue reading “Bones: Improved Technology is Bringing Loved Ones Home”
This post was contributed by guest blogger Tara Luther in the Genetic Identity group at Promega.
In July 2015, USA Today formed a partnership with journalists from over 75 Gannett-owned newspapers and TEGNA television stations to “perform the most detailed nationwide inventory of untested rape kits ever.” This article told the stories of rape victims who had lost hope of seeing the perpetrators of their assaults ever being brought to justice, even though DNA evidence was collected at the crime and was waiting to be analyzed.
The journalists working on this story uncovered more than 70,000 neglected rape kits in an open-records campaign that covered more than 1,000 police agencies. The story notes that “despite its scope, the agency-by-agency count cover[ed] a fraction of the nation’s 18,000 police departments, suggesting the number of untested rape kits reach[ed] into the hundreds of thousands.”
The USA Today effort led not only to national reporting but also to many local stories as well.
Forensic lab validations can be intimidating, so Promega Technical Services Support and Validation teams shared these tips for making the process go more smoothly.
Prepare Your Lab. Make sure all of your all of your instrumentation (CEs, thermal cyclers, 7500s, centrifuges) and tools (pipettes, heat blocks) requiring calibration or maintenance are up to date.
Start with Fresh Reagents. Ensure you have all required reagents and that they are fresh before beginning your validation. This not only includes the chemistry being validated, but any preprocessing reagents or secondary reagents like, polymer, buffers, TE-4 or H2O.
Develop a Plan. Before beginning a validation, take the time to create plate maps, calculate required reagent volumes, etc. This up-front planning may take some time initially, but will greatly improve your efficiency during testing.
Create an Agenda. After a plan is developed, work through that plan and determine how and when samples will be created and run. Creating an agenda will hold you to a schedule for getting the testing done.
Determine the Number of Samples Needed to Complete Your Validation. Look at your plan and see where samples can be used more than once. The more a sample can be used, the less manipulation done to the sample and the more efficient you become.
Select the Proper Samples for Your Validation. Samples should include those you know you’ll obtain results with be similar to the ones you’ll most likely be using, and your test samples should contain plenty of heterozygotes. When you are establishing important analysis parameters, like thresholds, poor sample choice may cause more problems and require troubleshooting after the chemistry is brought on-line.
Perform a Fresh Quantitation of Your Samples. This will ensure the correct dilutions are prepared. Extracts that have been sitting for a long time may have evaporated or contain condensation, resulting in a different concentration than when first quantitated.
Stay Organized. Keep the data generated in well-organized folders. Validations can contain a lot of samples, and keeping those data organized will help during the interpretation and report writing phase.
Determine the Questions to Be Answered. While writing the report, determine the questions each study requires to be answered. Determining what specifically is required for each study will prevent you from calculating unnecessary data. Do you need to calculate allele sizes of your reproducibility study samples when you showed precision with your ladder samples?
Have fun! Remember, validations are not scary when approached in a methodical and logical fashion. You have been chosen to thoroughly test something that everyone in your laboratory will soon be using. Take pride in that responsibility and enjoy it.
Need more information about validation of DNA-typing products in the forensic laboratory? Check out the validation resources on the Promega web site for more information for the steps required to adopt a new product in your laboratory and the recommended steps that can help make your validation efforts less burdensome.
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 “Rapid DNA Technology: Establishing your Identity in Less than Two Hours”
In central England, an archaeological dig is happening in an unlikely spot—a parking lot in the city of Leicester. The goal: To find the final resting spot of Richard III, the last of England’s Plantagenet kings and perhaps one of its most maligned rulers. Richard III reigned over England for only two years before being killed by Henry Tudor’s army during the Battle of Bosworth Field in August 1485 at the end of the War of the Roses, which pitted Richard’s House of York against the House of Lancaster. Many historical records suggest that Richard’s body was brought to Leicester and buried between the nave and altar at Grey Friars church. You would think that a king’s tomb would be well marked and well remembered, even for an unpopular king like Richard III, but that is not the case here. Henry was said to have erected a memorial for his former rival, but that and any other monuments, along with the church itself, are long gone, destroyed during the Dissolution of the Monasteries, when Henry VIII was named Supreme Head of the Church in England and systematically razed monasteries, convents and friaries throughout England, Wales and Ireland between 1536 and 1541. Since then, the exact location of Richard III’s remains was lost to history. However, thanks to a team of University of Leicester archaeologists and geneticists that might be changing.
Well, I just booked my plane tickets to Washington, DC., to attend the 22nd International Symposium on Human Identification (ISHI), which is being held October 3–6. I am excited because every year ISHI is filled with great presentations and posters that represent the newest advances in forensic science. Plus, I have opportunities to interact with some of the greatest minds in the field. These opportunities include more formal interactions, such as asking questions of presenters during the general session and poster sessions and “talking shop” during the breaks, lunches and evening events, but also informal interactions like chatting between mouthfuls of Texas barbecue (16th and 21st ISHI), line dancing (17th ISHI in Nashville, Tennessee), sipping Pinot Noir at a Hollywood hotspot (18th and 19th ISHI) and having pictures taken with a fairly convincing Elvis impersonator (20th ISHI in Las Vegas, Nevada).
Did you know that the microorganisms living in and on the human body (most on the skin, in the gut, and in the mouth) outnumber all our human cells by a factor of ten? But read on before you grab the hand sanitizer and schedule a colonic, these “germs” may be an integral part of what makes you… well “you”. Indeed, the profile of microorganisms happily living in and on your body may be as unique a signature as your DNA profile or your fingerprints—perhaps more so. Continue reading “How do I Describe Thee? Let Me Count the Ways”
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