Getting DNA or RNA into cells can be a tricky business, and a variety of transfection reagents have been developed over the years to make the process easier. Lipid-based reagents are especially popular because they combine efficient transfection with relatively low toxicity.
When it comes to transfection, it pays to think small. Human cells range in volume from 20–40 µm3 (sperm cells) to as large as 4 million µm3 (mature egg cells, or oocytes). For several decades, transfection reagents have targeted this size range. However, breakthrough research involves leaving the “micro” realm and entering a world that was once the domain only of science fiction: nanotechnology. Continue reading
Cloning is a fickle process that can make even the most seasoned bench scientists scream in frustration. By the time you perform a colony PCR and run the gel to check for your insert, you’ve invested several days in preparing these transformed cells. But then, the unthinkable happens. When you image your gel…the target band is missing.
This can trigger what’s known as “The 5 Stages of Failed Cloning Grief.” As you work through each stage at your own pace, just know that scientists all over the world feel your pain and can empathize with you in this difficult time. Continue reading
Yesterday, a series of 27 papers representing the most comprehensive genomic analysis of human cancers to date was published in Cell Press journals.
The collection constitutes the final outputs from the Cancer Genome Atlas (TCGA) project, a collaboration between the National Cancer Institute (NCI) and the National Human Genome Research Institute (NHGRI) involving analysis of over 11,000 tumors representing 33 different cancers. The many research teams involved analyzed tumor DNA, mRNA, miRNA and chromatin, comparing them to matched normal cellular genomes to perform a complete molecular characterization of cancer-specific changes. The results have been presented with much hope that open access to this type of comprehensive analysis will build on recent advances in understanding tumor biology and spur further progress in developing new approaches to treatment. (See this news item for more detail).
The Pan-Cancer Atlas results are collected on a cell.com portal, where they are presented in three collections grouped by topic: Cell of Origin, Oncogenic Processes and Signaling Pathways. Each collection is accompanied by a “Flagship” paper introducing the topic and summarizing the findings. It seems fitting that these findings have been published in #HumanGenomeMonth. This comprehensive analysis of the genomic and metagenomic profiles of tumors illustrates one powerful application of the type of genomic analysis pioneered by the original Human Genome Project, and shows just how much has been made possible since the initial publication of the human genome fifteen years ago. Continue reading
Your Promega Connections bloggers were sitting around reminiscing the other day, “Back when I was in the lab…”. Kind of like Thanksgiving Dinner among your elderly relatives, it wasn’t long before we were one-upping each other with horror stories from our days at the bench–stories that included escape artist rats, a leaky sequencing gel apparatus, and the iconic radioactively contaminated post doc.
We decided to turn that conversation, with a lot of help from our favorite science cartoonist Ed Himelblau, into retro Halloween costumes based on our memories of things we used to do in the lab that don’t seem like such a great idea now. Enjoy…and if you have a few retro horror science costume ideas of your own you would like to add, feel free to comment.
First up: Cesium Chloride Preps.
Let’s face it, most lab techs and purchasing agents aren’t all that happy when you send them an Instagram picture of your latest lunchroom-napkin cloning strategy as your order form for your next big cloning experiment. So we have created the CloneWeaver® Workflow Builder. You can transfer your brilliance easily from that lunchroom napkin to an orderly email or print out of every vector, enzyme, purification kit, and transfection reagent your next big molecular cloning experiment requires. You can even save your one-of-a-kind “cloning kit” for future endeavors.
The CloneWeaver® tool will walk you through every step of the molecular cloning process from selecting a vector to finding a transfection reagent for mammalian cells. So if you are starting a new project, we are with you every step of the way. We will help you find restriction enzymes and even remind you about markers and biochemicals that you may want to have on hand for your experiment. Within the tool we have links to additional resources like our RE Tool and catalog pages if you need more help.
Already have a favorite vector and a freezer full of restriction enzymes? No problem, skip those steps and move on to getting the perfectly sized nucleic acid markers or the particular polymerase your experiment requires.
Are you teaching a molecular genetics course? CloneWeaver® workflow builder is perfect for creating the list of laboratory reagents you are going to need for your students—and you will have this same list as a starting point for other lab experiments or classes later on because you can save the lists that you build. You can even pass them along to other professors.
So, if molecular cloning is in your future, let us help you get organized. Try the CloneWeaver® Workflow Builder.
Summer on the Prairie at Promega–Study science surrounded by birds, bees, flowers and amazing prairie.
Summer, a much-looked forward to season. We typically pack in the activities and make the most of the daylight. We work hard and we play hard. This summer will be no exception, and at the BTC Institute, we are already getting set to host as many students as we can. We will see middle and high schoolers, K-12 teachers, college students, graduate students, college and university faculty and staff, and professionals in the biotech community under our roof at some point. You may want to join us too!
Our programs for advanced learners, geared toward the graduate student or biotech professional, offer much more than just a rigorous immersion in molecular biology theory and practice. Held at the BTC Institute at Promega Headquarters, they are taught by highly knowledgeable scientists, coming from both industry and academia. These instructors offer a wealth of information and share their expertise as well as life experiences with students. Informal discussions about career trajectories and access to industry are important added benefits to attending these off-campus workshops. Continue reading
Kaukauna High School students arrive at the BTC for a biotechnology fieldtrip.
BTCI provides our students an opportunity that they could never get in the classroom.
—Jim Geoffrey, Biology Teacher, Kaukauna High School
Your bus has arrived and parked in the circular driveway at the front of the BioPharmaceutical Technology Center on the Promega Corporation campus in Fitchburg, WI. Your BTC Institute hosts – and instructors – for your field trip are Barbara Bielec (K-12 Program Director) and Ryan Olson (Biotechnology Instructor). They’ll greet you in the Atrium and direct you to a conference room where you can leave coats and backpacks, and then to the lab you’ll be working in during your visit.
Here’s a taste of what happened next for students from Random Lake High School and Wonewoc High School on December 3rd, and from Kaukauna High School on December 4th. Continue reading
Recently, one of my fellow bloggers described some of the advantages of using dual-reporter assays (including our Dual-Luciferase®, Dual-Glo® Luciferase and our new NanoDLR™ assay debuting soon). These assays are relatively easy to understand in principle. Use a primary and secondary reporter vector transiently transfected into your favorite mammalian cell line. The primary reporter is commonly used as a marker for a gene, promoter, or response element of interest. The secondary reporter drives a steady level of expression of a different marker. We can use that second marker to normalize the changes in expression of the primary under the assumption that the secondary marker is unaffected by what is being experimentally manipulated.
While there are many advantages to dual-reporter assays, they require careful planning to avoid common pitfalls. Here’s what you can do to avoid repeating some of the common mistakes we see with new users: Continue reading
Group Photo from the 2014 Core Techniques in Protein and Genetic Engineering Course Held at the BTC Institute July 14-18. Photo credit: BTCI
One of the things that I encourage all of the students I interact with in BTC Institute courses to do in order to boost retention and make meaning out of the activities that we do in class is to reflect on their experiences. Reflection is one way to connect new knowledge to past experience and get it to really stick in the brain, among other things.
Taking my own advice to heart, I use this space to ponder some interesting aspects of these experiences from my own perspective. This summer, I worked with 65 students and over 25 instructors to deliver four weeks of intensive instruction in molecular biology applied to a wide range of research areas. Continue reading
Today, reverse transcriptases are commonplace molecular biology tools, easy to obtain and routinely used in labs for everyday cloning and gene expression analysis experiments. Reverse transcriptase inhibitors have also found widespread use as antiviral drugs in the treatment of retroviral infections.
It’s easy to forget that the existence of reverse transcriptase activity—the ability to convert an RNA template into DNA—was once a revolutionary notion not easily accepted by the scientific community. The idea that RNA could be the template for DNA synthesis challenged the “DNA–>RNA–> Protein” central dogma of molecular biology.
The foundational studies that proved the existence of a reverse transcriptase activity in RNA tumor viruses were described in two papers published back-to-back in Nature in June, 1970. Two of the authors of these studies, Howard Temin of the University of Wisconsin and David Baltimore of the Massachusetts Institute of Technology, were awarded a Nobel Prize for their work in 1975.
In appreciation of the significance of these papers, the editorial introduction published in Nature at the time states:
This discovery, if upheld, will have important implications not only for carcinogenesis by RNA viruses but also for the general understanding of genetic transcription: apparently the classical process of information transfer from DNA to RNA can be inverted.
Before these papers were published, it was known that successful infection of cells by RNA tumor viruses required DNA synthesis. Formation of virions could be inhibited by Actinomycin D—an inhibitor of DNA-dependent RNA polymerase—so it was known that synthesis of viral RNA from a DNA template was part of the viral life cycle. The existence of an intracellular DNA viral genome was therefore indicated, and had been postulated by Temin in the mid 1960’s. However, proof of the mechanism whereby this DNA template was generated from the RNA genome of the infecting virus remained elusive. Continue reading