Traditionally, scientists have relied on flat, two-dimensional cell cultures grown on substrates such as tissue culture polystyrene (TCPS) to study cellular physiology. These models are simple and cost-effective to culture and process. Within the last decade, however, three-dimensional (3D) cell cultures have become increasingly popular because they are more physiologically relevant and better represent in vivo conditions.Continue reading “Reliable DNA Purification from 3D Cell Cultures”
“Dear Tech Serv,
We would like to detect DNA collected from swabs rubbed on the inside thighs of frogs. What would be the best DNA extraction kit to use for this?”
“Hi Tech Serv,
I need to find out a suitable kit for extracting DNA from bird fecal samples. Can I use ReliaPrep™ gDNA Tissue Miniprep System for that?”
These are just some examples of unconventional sample type inquiries that the Promega Technical Services Team receives regularly from scientists around the world. Many of these inquiries land in the hands of Technical Services Scientist, Paraj Mandrekar (a.k.a. “sample type guru”). Continue reading “Weird samples? Contact Tech Serv to find the right DNA purification kit for you.”
Isolating DNA from plant tissues is difficult for many reasons. Unlike animal cells, plant cells have rigid cell walls, often made of tough fibrous material, and contain proteins and enzymes and other compounds such as polysaccharides and polyphenols that play a role in different cellular processes. These compounds can interfere with DNA isolation as well as downstream applications such as PCR. For these reasons, DNA isolation methods that are used successfully for other sample types may not work well to isolate DNA from plant material. Continue reading “DNA Purification from Plants: Not All Methods are Equal”
Back in the dark ages, when I was a graduate student, my idea of “automated” plasmid DNA extraction involved performing home-brew, “toothpick preps” in “strip tubes” or , if I was really feeling ambitious, a 96-well plate. I would get just enough DNA to check for the presence of an insert, but the quality of the DNA was too low and the quantity too small to even consider using it for any other downstream experiments like amplification. And increased throughput for other nucleic acid extraction needs? Nope. If I wanted genomic DNA, RNA or high-quality plasmid DNA, I spent time with columns and tubes, giving each sample my undivided individual attention. Remember cesium chloride preps for RNA isolation? Even with the advent of column purification, which greatly simplified and standardized my protocols, nucleic acid purification was still a manual task that required a lot of time and effort to get the high-quality product I needed. Doing the experiments that would answer the questions that I really wanted to ask (those “downstream experiments”), meant spending time at the bench performing careful (if tedious) work to isolate and clean up the highest quality nucleic acid possible. Even then inconsistency in sample prep could wreak havoc on downstream work. Fortunately, for the modern scientist, personal, bench top automation, has progressed far beyond the toothpick and the strip tube to quality-tested, reliable nucleic acid extraction platforms like the Maxwell® Rapid Sample Concentrator (RSC). The Maxwell® RSC improves sample preparation consistency, eliminating variability associated with manual handling, and your downstream results will reflect this consistency. With the RSC you can extract DNA or RNA from up to 16 samples in approximately 1 hour and viral total nucleic acids in less than an hour. The instrument is easy to use: simply load the sample, push a button and walk away. Cross contamination is minimized and the instrument is supported by the Promega technical support and service you have come to trust over the past 35 years. Do you want to know more about how the Maxwell® RSC can become your research partner, giving you the freedom to focus on the work that interests you the most? Register for the free webinar and see the data for yourself: high-quality nucleic acid that performs well in downstream analyses. You’ll even be able to view videos illustrating RSC setup and use. Register today for the free webinar.
Guest Post from Promega Technical Services Scientist, Caroline Davis.
On a snowy day in January, someone stole the cookies that were to be served with lunch from the Rome Corners Intermediate School cafeteria. The kids were distraught. What should they do? Luckily, the Green 2 Team science class was there with Promega’s Technical Service Outreach team (and Paraj Mandrekar, Senior Research Scientist and Green 2 Team Dad) to help.
The students realized that the thief had taken a bite out of a strawberry and left part of it behind, along with his DNA. After a short discussion on what DNA is and why you would want to isolate DNA, the 6th graders extracted DNA from strawberries using household reagents under the guidance of the Promega scientists. The students used pipettors, beakers, microfuge tubes and flipper racks, giving the students a glimpse of the tools that scientists use everyday in in a molecular biology lab. Continue reading “Who Stole the Cookies? Technical Services Scientists Offer DNA Labs to Area Schools”
This is the webinar for you if you have ever wondered about the relative advantages and disadvantages of the many methods available for DNA purification, quantitation and analysis, or if you are comparing options for low- to high-throughput DNA purification. Eric presents a clear analyses of each of the steps in a basic DNA workflow: Purification, Quantitation, Quality Determination, and Downstream Analysis, providing key considerations and detailing the potential limitations of the methods commonly used at each step.
The DNA purification method chosen has an affect on the quality and integrity of the DNA isolated, and can therefore affect performance in downstream assays. Accuracy of quantitation also affects success, and the various downstream assays themselves (such as end-point PCR, qPCR, and sequencing) each have different sensitivities to factors such as DNA yield, quality, and integrity, and the presence of inhibitors. Continue reading “DNA Purification, Quantitation and Analysis Explained”
10. Means of transportation on the high seas or emergency flotation device (pumpkin boats; see the video).
9. Elementary Math Lessons. Determine circumference and radius. How much does a pumpkin weigh? Estimate the number of seeds. Check out pumpkin math ideas here.
8. Cholesterol-lowering snack. After ruthlessly scooping out the innards of a pumpkin, clean the seeds, bake them in the oven and enjoy your healthy snack. Pumpkin seeds contain phytosterols, compounds that that have been shown to reduce levels of LDL cholesterol, as well as magnesium, a mineral needed in the diet.