Plasmid vs. Genomic DNA Extraction: The Difference
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Plasmid vs. Genomic DNA Extraction: The Difference

Most experiments start with a piece of DNA—either plasmid DNA or genomic DNA. And your downstream uses for it dictate how much you need, what contaminants you can tolerate, and your extraction and purification methods. In this article, we explain the key differences between plasmid and genomic DNA extraction methods.

DNA Footprinting

DNA Footprinting

Studying DNA–protein interactions is an important aspect of molecular biology. Researches use a variety of methods to study these like the chromatin immunoprecipitation (ChIP) assay, electrophoretic mobility shift assay (EMSA), DNA pull down assay, luciferase reporter assay, filter binding assay, yeast one hybrid system, etc. Another interesting assay that helps investigate DNA–protein interactions is the…

Bacterial Transformation Troubleshooting for Beginners

Bacterial Transformation Troubleshooting for Beginners

The first time I did a transformation was when I worked with site directed mutagenesis. I cloned a protein sequence into the p15TVL vector, created my mutants (but that’s another story), and was finally ready for the next step: transformation and expression of my desired protein. Little did I know that my enthusiasm would fall…

The Good, the Bad and the Expensive of Whole Genome Sequencing

The Good, the Bad and the Expensive of Whole Genome Sequencing

Whole Genome Sequencing (WGS) is still very cutting edge, sequencing technology and while there are a lot of perks to using it, there are also a few drawbacks. The good, the bad and the pricey are outlined below to help you navigate when it’s worth using WGS! Whole Genome Sequencing: The Good Lots of Data…

An Introduction to Nanopore Sequencing

An Introduction to Nanopore Sequencing

DNA sequencing is the most powerful method to reveal genetic variations at the molecular level, leading to a better understanding of our body in physiological settings, and pathological conditions. It is the beginning of the long road towards better diagnostics and personalized medicine. Even though there have been great advances in DNA sequencing technologies there…

Using Synthetic DNA For Long Term Data Storage

The amount of data requiring long-term storage is growing and accelerating. Current long-term digital storage technology cannot keep up. Imagine roughly 2.5 QUINTILLION bytes of data being created everyday in this world1–2 as more computers and network infrastructure come online. For average users, a long-term storage solution is probably not an issue. However, organizations and…

PCR Pitfalls: The Devil is in the Details

PCR Pitfalls: The Devil is in the Details

PCR was actually one of the first lab techniques I learned as an undergrad. Despite being sometimes labeled as a pretty basic lab skill, PCR doesn’t always work as expected. This “fickle” success is due to small details or hidden hazards within the PCR workflow that can cause your seemingly uncomplicated experiment to fail.  This…

Demystifying NGS: Depth Coverage and Deep Sequencing

Demystifying NGS: Depth Coverage and Deep Sequencing

NGS is not a three-headed monster. However, it can be a difficult concept to grasp—especially when you are getting started.  There is a lot of new terminology, and a whole new world to discover: both in the lab bench and in interpreting your results. It helps to start somewhere. So, let’s start! Depth of Coverage…

Small Particles (Things) Matter!- Introducing Nanoparticle PCR

Small Particles (Things) Matter!- Introducing Nanoparticle PCR

There are many different methods and protocols on making your PCR  run more efficiently. I recently came across an interesting PCR method called “nanoparticle” PCR. This method seems to attract a lot of attention, because it enhances a PCR  by a few orders of magnitude. More interestingly, while the enhancement effect has been reported in a…

Cloning Large or Complex DNA Fragments

Cloning Large or Complex DNA Fragments

Sometimes you know a project is going to be a pain before you even start it. For me, that is whenever I need to clone large (> 3 kb) or complex (e.g., a sequence with repeats) DNA fragments. Long and complex DNA fragments are more likely to create challenges during cloning. Such projects require extra care in just about…

How DNA Extraction Is Different in Plants

How DNA Extraction Is Different in Plants

I know what you are thinking, everything is made of cells, so how different can DNA extractions be in plants? The answer is… sort-of different. The overall concept is the same. Cell membranes are lysed, DNA is separated from other cell materials, washed a few times, and then resuspended in water or Tris-EDTA buffer (aka…

AAV Production Part II: Virus Purification

AAV Production Part II: Virus Purification

In Part I of AAV Production, I described how to produce crude (non-purified) AAV. In this article, I am going to tell you how to purify that crude prep. Virus purification is usually done by gradient ultracentrifugation. Two common methods involve gradients made from increasing concentrations of cesium chloride or iodixanol. A cesium chloride prep…

Pre-Analytical Sample Handling: What Can You Do Better?

Pre-Analytical Sample Handling: What Can You Do Better?

If you study human disease, you will likely handle a pre-analytical sample or two (or hundreds).  For example, you could handle whole blood, serum or plasma, tissue biopsies, urine, fecal samples, cerebrospinal fluid, or synovial fluid—to name a few. You will probably use these samples to look for specific metabolites, proteins, or nucleic acids that provide…

Introduction to Linux for High-Throughput Sequencing Analysis

Introduction to Linux for High-Throughput Sequencing Analysis

So, you’ve spent time planning your high-throughput sequencing experiment. You’ve chosen how many replicates to use, deliberated about sequencing depth, and kept everything RNase-free. Now you have many gigabytes of data available. What’s next? While the first step of RNA-Seq analysis is aligning your sequencing reads to a reference genome, first you need to get…

Acid Phenol Chloroform Extraction of DNA, RNA and protein:  3 in 1

Acid Phenol Chloroform Extraction of DNA, RNA and protein: 3 in 1

In austerity times, nothing is in excess. Apart from saving reagents, which can be refilled with extra financial injections, there is a commodity that cannot be easily resupplied – tissue samples! If, like me, you have experienced the fear of not having enough sample for performing a qPCR, western blot, and conventional PCR from the…

Pulsed Field Gel Electrophoresis:  Tips and Tricks

Pulsed Field Gel Electrophoresis: Tips and Tricks

Running a pulsed field gel can be exciting. It isn’t often that you get to visualize such large pieces of DNA. However, it can also be extremely frustrating. It isn’t uncommon to wait 24 hours only to find out that your DNA was degraded before you started the run. Then, you have to start all…

An Introduction to Shotgun Sequencing:  Fire in the Hole

An Introduction to Shotgun Sequencing: Fire in the Hole

In the midst of all the cool new sequencing techniques and technologies out there today, you may have overlooked the tried and true method of Shotgun Sequencing. What is Shotgun Sequencing Anyway? Shotgun sequencing gets its name from the concept that a large sequence is essentially broken up in to many, many smaller pieces, similar…

Pulsed Field Gel Electrophoresis – The Basics

Pulsed Field Gel Electrophoresis – The Basics

You have probably run a standard agarose gel hundreds of times. They are great for visualizing small DNA fragments up to 10 kb, but what if you want to examine really large pieces of DNA or even whole chromosomes? This is where pulsed field gel electrophoresis (PFGE) comes in! While the equipment required to run…