This blog was written by guest blogger and 2018 Promega Social Media Intern Logan Godfrey.
Only 30 years ago, the polymerase chain reaction (PCR)
was used for the first time, allowing the exponential amplification of a specific
DNA segment. A small amount of DNA could now be replicated until there was
enough of it to study accurately, even allowing sequencing of the amplified DNA.
This was a massive breakthrough that produced immediate effects in the fields
of forensics and life science research. Since these technologies were first
introduced however, the molecular biology research laboratory has been the sole
domain of PCR and DNA sequencing.
While an amazing revolution, application of a technology
such as DNA sequencing is limited by the size and cost of DNA sequencers, which
in turn restricts accessibility. However, recent breakthroughs are allowing DNA
sequencing to take place in jungles, the arctic, and even space—giving science
the opportunity to reach further, faster than ever before.
The newfound accessibility of DNA sequencing means a
marriage between fields of science that were previously largely unacquainted.
The disciplines of genomics and wildlife biology/ecology have largely progressed
independently. Wildlife biology is practiced in the field through observations
and macro-level assessments, and genomics, largely, has developed in a lab
setting. Leading the charge in the convergence of wildlife biology and genomics
is Field Projects International.
On January 23, doctors, scientists and researchers will gather for a symposium about Microsatellite Instability (MSI) at Duke University. During the one-day event, scientists from Duke University and The Ohio State University will share insight into their research on biomarkers, MSI status and GI cancer, Lynch Syndrome, and MSI and DNA mismatch repair deficiency (dMMR).
The 2018 Nobel Prize in Physiology and Medicine was awarded to James P. Allison of the United States and Tasuku Honjo of Japan for their work to identify pathways in the immune system that can be used to attack cancer cells (1). Although immunotherapy for cancer has been a goal for many decades, Dr. Allison and Dr. Honjo succeeded through their manipulation of “checkpoint inhibitor” pathways to target cancer cells.
Immune checkpoint inhibitor drugs have been effective in cancers such as aggressive metastatic melanoma, some lung cancers, kidney, bladder and head and neck cancers. These therapies have succeeded in pushing many aggressive cancers below detectable limits, though these cases are notably not relapse-free or necessarily “cured” (2,3).
One challenge in implementing immunotherapy in a cancer treatment regime is the need to understand the genetic makeup of the tumor. Certain tumors, with specific genetic features, are far more likely to respond to immune checkpoint therapy than others. For this reason, Microsatellite Instability (MSI) analysis has become an increasingly relevant tool in genetic and immuno-oncology research.
Today’s post was written by guest blogger Anupama Gopalakrishnan, Global Product Manager for the Genetic Identity group at Promega.
Next-generation sequencing (NGS), or massively parallel sequencing (MPS), is a powerful tool for genomic research. This high-throughput technology is fast and accessible—you can acquire a robust data set from a single run. While NGS systems are widely used in evolutionary biology and genetics, there is a window of opportunity for adoption of this technology in the forensic sciences.
Currently, the gold standard is capillary electrophoresis (CE)-based technologies to analyze short tandem repeats (STR). These systems continue to evolve with increasing sensitivity, robustness and inhibitor tolerance by the introduction of probabilistic genotyping in data analysis—all with a combined goal of extracting maximum identity information from low quantity challenging samples. However, obtaining profiles from these samples and the interpretation of mixture samples continue to pose challenges.
MPS systems enable simultaneous analysis of forensically relevant genetic markers to improve efficiency, capacity and resolution—with the ability to generate results on nearly 10-fold more genetic loci than the current technology. What samples would truly benefit from MPS? Mixture samples, undoubtedly. The benefit of MPS is also exemplified in cases where the samples are highly degraded or the only samples available are teeth, bones and hairs without a follicle. By adding a sequencing component to the allele length component of CE technology, MPS resolves the current greatest challenges in forensic DNA analysis—namely identifying allele sharing between contributors and PCR artifacts, such as stutter. Additionally, single nucleotide polymorphisms in flanking sequence of the repeat sequence can identify additional alleles contributing to discrimination power. For example, sequencing of Y chromosome loci can help distinguish between mixed male samples from the same paternal lineage and therefore, provide valuable information in decoding mixtures that contain more than one male contributor. Also, since MPS technology is not limited by real-estate, all primers in a MPS system can target small loci maximizing the probability of obtaining a usable profile from degraded DNA typical of challenging samples. Continue reading “Is MPS right for your forensics lab?”
Today’s blog is contributed by guest blogger Caitlin Cavanaugh, Client Support Consultant with Promega North America.
Recently, I began a new role as a client support consultant at Promega. In this role, I’m responsible for all technical and sales support for the Promega portfolio in the New Jersey and Philidelphia area.
Before coming to Promega, I worked in a lab at a start-up company right out of college, then made my way into sales, where I worked for a leading life-science instrumentation company for thirteen years.
Held May 2018, Means and Metrics for Detecting and Measuring Consciousness was designed to explore emerging technologies for studying the phenomenon of consciousness, including research related to sleep, wakefulness, altered states, focused attention and coma. We asked the question: How might our ability to better measure consciousness create opportunities to improve human function, resolve disease states and keep the mind and brain throughput all stages of life?
In the United States, the last Monday of May is Memorial Day, a national holiday in which we honor those who have given their lives in service to the country. For those of us living in Wisconsin, Memorial Day is also usually preceded by the first truly warm weekend of summer. So as families remember their loved ones, they gather together to create new memories in parks and backyards, around picnic tables or on grassy lawns–beginning the summer season of cookouts, picnics and bar-b-ques.
Here at Promega we love a good cookout too. So a few of us have cobbled together some of our favorite summer recipes to share with you. Do you have a favorite summer recipe? Share it in the comments below. (Please note metric conversions are approximate and have not been tested.) Continue reading “Kicking Off Summer with Some Cookout Favorites”
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 “Which DNA Do I Use? How to Choose Your Control and Other DNA Samples”
Today’s Promega Connections blog is written by guest blogger Tori Sheldon, North America Marketing and Events Coordinator.
It is crazy to think how quickly the months fly by. It feels like yesterday I was watching the ball drop as 2017 turned to 2018. Now it is almost March, when Wisconsin starts to emerge from the cold winter. March also happens to be National Optimism Month.
As I think about optimism, I am reminded of one of the core values that guide interpersonal relationships at Promega: “look for the good, with discernment”. The spirit of this value is to remember that deep down everyone is trying to come from a positive place and that even though we may not always agree with each other it is an opportunity for further discussion and collaboration.