DNA / RNA Manipulation and Analysis
Show Your Molecular TALEN(T)
Introduction Did you know that the idea of using genetic engineering to ameliorate certain human diseases was viewed as ‘science fiction’ only 10 short years ago? While cell mutagenesis studies and genetic knockout experiments were feasible before genetic engineering, they were not very reliable. Indeed, due to the random and imprecise nature of these older…
Read MoreNGS Target Enrichment Strategies
Next-generation sequencing (NGS) has ushered in a new era of understanding of both the inner workings and the function of the genome. NGS allows researchers to look at traits—including diseases—that are linked to differences or mutations in an individual’s genes. Since only about 1% of the human genome constitutes genes that code for proteins, several…
Read MoreThe EMSA – Teaching an Old Dog New Tricks
Probing Nucleic Acid-Protein Interactions with EMSA The electrophoretic mobility shift assay (EMSA) is a powerful technique for detecting specific-binding of nucleic acid-protein complexes. Over the past 30 years, EMSA has been the “go to assay” to investigate the qualitative interactions between nucleic acids (DNA or RNA) and nucleic-acid binding proteins. Through the use of radio-labeled…
Read MoreIsolating Bacterial RNA from Blood
For many decades, the only way to detect sepsis – bacterial growth in blood – was isolating the bacteria and growing bacterial colonies on a special medium. This was done by first spinning down the blood, which brought the blood cells and bacteria into the pellet. The pellet was spread on a blood agar plate…
Read MoreHow (and Why) to Label Nucleic Acids
Have you ever wished you could snag individual strands of DNA or RNA with a lasso? Or look at them one by one, figuring out exactly where they are or what they are doing? Fortunately, there are techniques that exist to label nucleic acids for their visualization and purification! Nucleic acids can be labeled at…
Read MoreThe Beginner’s Guide to Reading Plasmid Maps
Very often plasmid maps, especially historical ones that are hand-drawn by a long-forgotten PhD student, are a puzzle. What are these arrows and boxes? Where do I start? Don’t worry, we have a crash course introduction into deciphering plasmid maps. Familiarizing Yourself with Your Plasmid of Interest Let’s start with a classic plasmid: pBR3221. It…
Read MoreRNAseq Library Preparation: From Cells to cDNA
RNAseq libraries, also called whole transcriptome shotgun sequencing libraries, provide a snapshot of cellular processes. This allows the researcher to gain information regarding changes in transcriptome in response to environmental changes, during disease, or after a drug application. RNAseq libraries also allow for the detection of mRNA splicing variants and SNPs. RNAseq libraries have virtually…
Read MorePicking the Right DNA Isolation Kit for Your Application
If you plan to work with purified DNA in the lab, it’s likely that you will use a commercial DNA extraction kit to isolate and purify your DNA of interest. With so many types of kits available, it can be a major challenge to choose the best one to use when working with an unfamiliar…
Read MoreAre You In(to) Situ? – Putting Together Your First RNAscope® Assay
You are thinking of trying out RNAscope®. After all, RNAscope® holds promise for increasing the sensitivity and specificity of your in situ hybridization. Yet, getting started can be a little overwhelming with the numerous kits and reagents available in the RNAscope product line. Here’s an overview of your options to help you navigate to the…
Read MoreRNA Strandedness: A Road Travelled In Both Directions
For most molecular biology purposes, DNA is thought of as a string of nucleotides running from 3’ to 5’, and the corresponding mRNA sequence is complementary to this DNA string. However, visualizing this quirky DNA structure for what it is – two antiparallel strands joined together – it quite important for many applications, such as…
Read MoreThe Next Big Thing: Alternative Polyadenylation
What Is Alternative Polyadenylation? Processing of mRNA and its regulation plays a fundamental role in gene expression. As science progresses, alternative polyadenylation takes center stage in the undercurrents of gene expression. 1,2 Polyadenylation is part of the pre-mRNA maturation process and involves polyadenylation of the 3’ end of the emerging RNA. This process happens to…
Read MoreThe Importance of Non-coding RNAs
What Are Non-Coding RNAs? What was once considered “junk” may end up being the most important part of our genome. Non-coding RNA (ncRNA) is RNA that is transcribed from DNA but diverts from the “central dogma” because it does not code for proteins. NcRNAs are ubiquitous in eukaryotes: while 90 percent of eukaryotic genomes are…
Read MoreProtocols for Cloning Without Restriction Enzymes or Ligases
There are many cloning methods that do not require restriction enzymes or ligases. Read below to learn about how to achieve seamless cloning results via Topoisomerase cloning, SLIC, and Gibson. Method #1: Topoisomerase Technology Topoisomerase technology requires no special primers and no ligases – it is as easy as cloning comes. This technology is based…
Read MoreCloning Methods: 5 Different Ways to Assemble
Over the past few decades molecular biologists have developed procedures to simplify and standardize cloning processes, allowing vast arrays of artificial DNA structures to be more easily assembled. Are you familiar with all the cloning options out there? Let’s look at five different cloning methods you can use to get your construct. At the end…
Read MoreLigation Independent Cloning Primer Design
Ligation independent cloning (LIC) is an easy and effective method to ensure successful cloning, all without the need for ligation. As easy as the technique is, designing primers can be a bit tricky. In this article, we will present a quick overview on primer design for ligation independent cloning.
Read MoreA Beginner’s Guide to Lentiviral Transduction
The use of viral delivery systems to transduce cells for gene and protein investigations has become prominent over the last 20 years. In particular, the use of lentiviral vectors permits stable expression of your gene of interest. This is all possible with a little bit of nucleic acid magic. Lentiviruses (a genus of retrovirus) express reverse…
Read MoreOld Reliable: Two-Step Allelic Exchange
Manipulating the genes of organisms is crucial for studying their functions. In times before genetic engineering, scientists would shoot bacteria with X-rays or expose them to destructive chemicals until spontaneous mutations would arise. Fortunately, current methods are more sophisticated and less torturous. Researchers now use more directed techniques to introduce mutations. There are several ways…
Read MoreRNA Isolation from Drosophila – Don’t Let the Cuticle Scare You!
Isolating RNA from either Drosophila larvae or adult heads can seem a bit daunting, primarily due to the presence of the cuticle. The cuticle is a protective exoskeleton comprised of insoluble collagens, cuticlins, glycoproteins, and lipids. While it may take some force to remove the cuticle, you can do this easily and without compromising your…
Read MoreSmall Differences that Matter: Detecting Microsatellite Polymorphisms
If you have any training in genetics, chances are that during the course of your education you ran into those funny little sequences called microsatellites. These are repeated tandem motifs 1-6 nucleotides long, scattered all over our genomes. These used to be called “junk DNA,” because researchers thought that the repeats served no purpose. Nowadays,…
Read MoreDNA 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…
Read MoreExtracting Circulating microRNA
Thinking about studying extracellular RNA and in particular microRNA? Read on for some great tips for extracting circulating microRNA.
Read MoreBacterial 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…
Read MoreRestriction Enzymes: Five Things to Consider Before you Chop!
The use of restriction enzymes to characterize DNA has been popular since the 1970s. Today, this “old school” technique is still one of the easiest and fastest ways to assess DNA sequences. Like most lab reagents, restriction enzymes can be fickle and you should bear a few things in mind when using them. Generally, sticky-ended enzymes have greater…
Read MoreThose Site-Specific Recombinases in Your Tool Kit
Most of us are aware of genetic engineering systems like Cre-Lox, TALENs, Zinc finger systems, and of course, CRISPR-Cas9. These are all examples of CSSR- Conservative Site-Specific Recombination. We use these site specific recombinases routinely, but do we really know about them or what the future hold for these tools? It turns out that CSSR…
Read MoreUsing 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…
Read MoreFISHing for miRNAs in Archived Tissues? Yes, It Is Possible!
We use fluorescent in situ hybridization (FISH) techniques routinely to detect DNA or RNA sequences in tissues, but what about micro RNAs (miRNAs)? No worries, FISH is now optimized to meet the challenge. To help you get going with the method, here’s what you need to know. The first thing that comes to mind when…
Read MoreTransfection Toolkit
Engineering a mutation or overexpressing a recombinant protein to study and characterize its function in mammalian cells is no easy task. Luckily, Chinese hamster ovary (CHO) cells, which have been a mainstay in the lab since the 1950s, represent a relatively easy mammalian model system to engineer. There are several methods to choose choose from…
Read MoreGet Your Polymerase Cycling Assembly Oligos Together
The polymerase chain reaction (PCR) is the backbone of many lab techniques. In short, it allows for the exponential amplification of a specific segment of DNA. Through the use of primers encoding restriction enzyme sites, these amplified fragments are used in downstream cloning procedures, usually leading to the insertion of one, maybe two, PCR fragments…
Read MoreHow to Perform DNA Extraction from Dried Blood Spots Using Chelex Resin
Every bio- scientist who wants to analyze DNA knows that the process begins with the extraction of DNA from cells of interest. These cells could be RBCs, parasites, or bacteria to name a few. Furthermore, there are various DNA extraction methods1 to choose from depending on sample type, downstream analysis, and so forth. Many scientists…
Read MoreBenzyl Isoamyl Alcohol: a Novel, Bizarre, and Effective DNA Purification Tool
DNA Purification We all use our favorite techniques for DNA cloning, such as Gibson assembly, TOPO cloning, ligation independent cloning (LIC), and TA cloning. However, DNA purification methods themselves, haven’t changed all that much since the 90’s. Historically, the introduction of phenol extraction in 1956, to purify nucleic acids from rat liver, rapidly replaced previous…
Read MoreTips and Tricks to Get Around Low Plasmid Yields in Agrobacterium tumefaciens
A while back, one of our readers asked for a quick and easy and quick way to extract plasmids from transformed Agrobacterium tumefaciens cells. They pointed out that plasmid copy number is often low in Agrobacterium and that yield can be poor in alkaline base miniprep protocols. The short answer is that there is no…
Read MoreQuantifying & Assessing RNA: TE or not TE?
Red Pill or Blue? Carrying out science often involves many difficult decisions! I see it all the time in RNA protocols – the “gracious” option of using purified water or Tris-EDTA (TE) buffer to dissolve (or elute, if you are using column purification) RNA. When I was trained in assessing RNA using UV spectrophotometry, graduate…
Read MoreFour Ways to Get CRISPR Reagents Into Your Cells
Read up on the various methods for delivering CRISPR reagents and how to choose between them.
Read MoreBenefits of the GUS Gene Reporter System in Plants
Gene reporters enable valuable insight into gene expression. The GUS gene reporter system is one of the popular and common plant reporter systems. GUS, is short for glucuronidase, an enzyme in the bacterium E. coli. GUS is a good reporter for plants, as it does not occur naturally, and thus, has a low background. With…
Read MoreCloning 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…
Read MoreHow 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…
Read MoreCRISPR Technology Explained: Towards a CRISPR Genome!
Grab an overview of CRISPR technology from its roots as a bacterial defense system to how it can be utilized in health and research.
Read MoreViral Vector Production: Myths & Misconceptions
Viral vector production is a worthwhile skill that can be made even easier with a few tips and tricks. In general, transfection of multiple plasmids into a producer cell line results in infectious, non-replicative virus. However, it is important to ensure that your vector preparation is efficient, giving your experiments the best chance of success.…
Read MoreAAV 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…
Read MoreAcid 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…
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