DNA isolation

Finding the Right Maxwell® RSC Kit for Your Nucleic Acid Extraction

Posted on by Promega

This blog was written by guest writers Paraj Mandrekar (Technical Services Scientist 3) and Michelle Mandrekar, (Research Scientist 4).

Here are some designer’s notes comparing the Maxwell® RSC Blood DNA and the Maxwell® RSC simplyRNA kit chemistries for nucleic acid extraction.

The Maxwell RSC Blood DNA Kit and Maxwell RSC simplyRNA Blood Kit were both developed from the same non-silica-based purification chemistry and use the same underlying paramagnetic particle. This chemistry is characterized by an extreme binding capacity (the capacity of nucleic acid that can be bound on the particle), leading to both chemistries being capable of isolating large amounts of nucleic acid volumes and then eluting into relatively small volumes (50 µL). It is not unusual with either chemistry to have isolates that exceed 100 ng/µL. Although the chemistries have several similarities, there are some important distinctions between how the two chemistries were designed that influence which kit you choose for your nucleic acid extraction.

Image of blood with molecules of DNA and RNA superimposed Nucleic Acid Extraction
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Do you want to build a snowman? Developing and optimizing a qPCR assay to detect ice-nucleating activity

Posted on by Michele Arduengo
Snowflakes---MA-400x600

Over the last few months we have published several blogs about qPCR—from basic pointers on avoiding contamination in these sensitive reactions to a collection of tips for successful qPCR. Today we look in depth at a paper that describes the design and and optimization of a qPCR assay, and in keeping with the season of winter in the Northern hemisphere, it is only fitting that the assay tests for the abundance and identity of ice-nucleating bacteria.

Ice-nucleating bacteria are gram-negative bacteria that occur in the environment and are able to “catalyze” the formation ice crystals at warmer temperatures because of the expression of specific, ice-nucleating proteins on their outer membrane. Ice-nucleating bacteria are found in abundance on crop plants, especially grains, and are estimated to cause one-billion dollars in crop damage from frost in the United States alone.

In addition to their abundance on crop plants, ice-nucleating bacteria are also found on natural vegetation and have been isolated from soil, snow, hail, cloud water, in the air above crops under dry conditions and during rain fall. They have even been isolated from soil, seedlings and snow in remote locations in Antarctica. For the bacteria, ice nucleation may be a method to promote dissemination through rain and snow.

Although ice-nucleating bacteria have been isolated from clouds, ice and rain, little is known about their true contribution to precipitation or other events such as glaciation. Are such bacteria the only source of warm-temperature (above temperatures at which ice crystals form without a catalyst) ice nucleation? Can they trigger precipitation directly? What are the factors that trigger their release from vegetation into the atmosphere? Can we determine their abundance and variety in the environment?

Continue reading “Do you want to build a snowman? Developing and optimizing a qPCR assay to detect ice-nucleating activity”

Freedom to Focus: Maxwell® Rapid Sample Concentrator

Posted on by Michele Arduengo
Wish I had one of these when I was at the lab bench...
Wish I had one of these when I was at the lab bench…

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. 

Want to know more about how the Maxwell® RSC can give you the freedom to focus on the work that interests you the most? To learn more, click here.

ProK: An Old ‘Pro’ That is Still In The Game

Posted on by Nives Kovacevic
Proteinase K Ribbon Structure ImageSource=RCSB PDB; StructureID=4b5l; DOI=http://dx.doi.org/10.2210/pdb4b5l/pdb;
Proteinase K Ribbon Structure ImageSource=RCSB PDB; StructureID=4b5l; DOI=http://dx.doi.org/10.2210/pdb4b5l/pdb;

If you enter any molecular lab asking to borrow some Proteinase K, lab members are likely to answer: “I know we have it. Let me see where it is”. Sometimes the enzyme will be found to have expired. The lab may also have struggled with power outages or freezer malfunctions in the past. But the lab still decides to keep the enzyme. One may rightly ask – why do labs hang on to Proteinase K even when it has been stored under sub-standard conditions?

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