Tips and Tricks to Get Around Low Plasmid Yields in Agrobacterium tumefaciens

Tips 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…

How to Store Your Concentrated Proteins

Like graduate students, proteins are sensitive to rough handling. This is particularly true when they (the proteins, not the students!) are being concentrated, purified, and stored. We’ve covered the many options out there for concentrating your proteins, along with how to handle protein extracts to keep your proteins safe from degradation. But proteins can degrade…

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How to Choose Quality Antibodies for Successful Western Blotting

Successful western blotting means achieving unambiguous results, and this requires a sensitive and specific antibody-antigen interaction. Consequently, high quality antibodies are critical for reliable and consistent western blotting. Western Blotting Process In the basic western blotting process, polyacrylamide gel electrophoresis (PAGE) separates a mix of proteins according to their molecular weights (denaturing gels) or their…

reagents

How to Store Your Reagents, so They ‘Do Exactly What It Says on the Tin’

Your reagents should do ‘Exactly what they say on the tin.’  This only happens though if you look after them in the way the manufacturer states on their data sheets. We have all been guilty of using reagents past their expiration date.  Usually we can get away with it, but there are a few things…

Fluorescent Western Blotting: Lowdown and Advantages

In this article, you will be introduced to the world of fluorescent western blotting. Firstly, we will compare fluorescent and chemiluminescent western blotting. Then, we will learn how infrared fluorescent western blotting can give you truly quantitative and reproducible results. Lastly, we’ll look at the many advantages of fluorescent western blotting, including the possibility to multiplex. Importantly,…

Setting up a Fermentation or Perpetuum Mobile Cell Culture

Setting up a Fermentation or Perpetuum Mobile Cell Culture

Some names are confusing. For example, ant-lion is not an ant – or a lion. Likewise, fermentation in the scientific sense does not involve using a ferment or brewing beer. In science, fermentation is the setting up of a long-term culture of eukaryotic or prokaryotic cells. Fermentation is invaluable in providing a steady flow of…

Quantifying & Assessing RNA: TE or not TE?

Quantifying & 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…

droplet digital PCR

Divide and Conquer: How to Setup Your First Droplet Digital PCR Experiment

Droplet digital PCR?  It’s easy. Because we’re here to guide you through it. We recently introduced you to the principles of digital PCR technology and how it differs from qPCR. In a nutshell, digital PCR is an end-point PCR technology that divides a single PCR into a large number of partitions, and then perform PCR…

Choosing The Best RT-qPCR Method

How to Choose the Correct Reverse Transcription Method

Quantitative Reverse transcription PCR (RT-qPCR) is frequently used in the lab to detect and quantify RNA expression in a sample. The first step of the assay is to convert the labile RNA to its complementary DNA (cDNA) counterpart through reverse transcription (RT). In fact, RT is the first step in a variety of molecular biology…

methylation

A Primer on Checking the Methylation State of the Genome

We all know that genes encode proteins that make up a living cell. However, the level and coordination of gene expression is really the key to the success of a living cell. One way eukaryotic cells (that’s us!) control protein expression is through addition of a methyl or hydroxymethyl group on the cytosine nucleotide. This…

Are Quantum Dots Any Good for Flow Cytometry?

Are Quantum Dots Any Good for Flow Cytometry?

What Are Quantum Dots? Quantum dots were discovered in the early 1980s. However, it was not until the late 1990s that their use in biological applications was suggested.1 Quantum dots are semiconducting nanocrystals made of artificial atom clusters. Their size generally ranges from 2 to 20 nm. Size is crucial for their physical properties because…

Titering Phage – Counting Something Invisible with Something Only Slightly More Visible

Titering Phage – The Plaque Assay Phage display is a molecular technique used to isolate binding or interaction partners to molecules of interest from an extensive library. Such libraries are often derived from the variable regions of native B-cell antibody-binding genes cloned into phage DNA. A single round of phage display panning involves many important steps. However, the…

How to perform cell synchronization in specific cell cycle phases

How to perform cell synchronization in specific cell cycle phases

The cell cycle has been very well documented over the years because of its dysregulation in diseases such as cancer. Many different processes contribute to cell growth and replication, which is ultimately controlled by a series of tightly controlled cell cycle phases. For some areas of research, especially within drug discovery and cancer research, cell synchronization in…

Proteomics and Good Mass Spectrometry Data

It is currently possible to analyze thousands of proteins in a single sample using mass spectrometry (MS) and a database of predicted protein sequences, referred to as ‘bottom-up’ proteomics. With this technology, you can measure protein levels and interactions. Also, you can examine changes in post-translational modifications (PTMs) and isoforms (in an unbiased manner). Working with…

Benefits 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…

plyogenetic tree construction

Phylogenetic Tree Construction Made Easy with Blast & Mega

Your DNA sequence can be put to good use fairly easily with Blast and Mega software. These programs can help in phylogenetic tree construction. You can ask questions like what is the evolutionary relationship between a set of sequences from different species? Or how have certain microbial strains arisen? Blast As any bioscientist probably knows,…

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…

semiquantitative scoring

Analyze Immunostained Slides with Semiquantitative Scoring

A  routine task in the lab is to investigate the presence of your favorite protein in a range of histological samples. No doubt, staining your tissue sections using good old immunohistochemistry (IHC) would be your first choice. You just got to love a technique that has celebrated its 70th birthday, and is still used in…

Clean up structure

ChemDraw: a Versatile Molecule Sketching Tool for (Bio)Chemists

Have you ever wondered how to make professional, easy-to-understand figures of molecules for presentations or publications? While several programs exist for this purpose, ChemDraw is like the Swiss Army knife of chemical sketching programs that most chemists and journals use to prepare figures. Beyond the ability to create chemically accurate and legible figures, ChemDraw can…

cytometer

The Difference Between an Image, Flow, Time-lapse and Cell-sorting Cytometer

Ah, cell counting — it’s the oldest trick in the book! Well, not really, but people have been developing methods for counting cells since the late 1800s. It has been around for a while. But what different methodologies are available to biologists now? Well, hold on, because you’re in for a treat! In this article, we…

Laboratory Animal Ethics: The Three Rs

Laboratory Animal Ethics: The Three Rs

Animal models have helped make enormous discoveries and breakthroughs in the last few decades. From Pasteur’s use of sheep to test the ‘Germ Theory’, Pavlov’s classic conditioning experiments in dogs, to Dolly the first cloned mammal, animal research has come a long way. Today, most drugs, vaccines and other pharmaceutical products for medical use are…

Extracting Better Ubiquitin Data from Your Samples: Beyond the Cellular Skip

Extracting Better Ubiquitin Data from Your Samples: Beyond the Cellular Skip

The ubiquitin-proteasome system was discovered at the start of the 1980s, and people have been studying it ever since. Initially, researchers thought that tagging a protein with ubiquitin was the cell’s signal for the protein to be scrapped via the proteasome. But more research has shown that, as with all biology, once you’re up close and…

How to Generate High-Quality SNPs Data Sets from NGS

SNPs or single nucleotide polymorphisms are on many scientist’s wish list in experimental studies of genomic DNA sequences. Methods to detect SNPs have evolved. Now with the availability of high throughput sequencing methods, also known as next generation sequencing (NGS), SNPs can be identified in the large amounts of DNA sequence that is generated. There…

SNPs eQTL

Investigating an Expression Quantitative Trait Locus (eQTL)

Thousands upon thousands of genetic variants are now associated with every disease and trait you can possibly think of. Such traits range from cancers to blood pressure, intelligence, height, weight… and many more! This is largely because of the advent of genome-wide association studies (GWAS). However, the vast majority of genetic loci associated with these traits are…

Tips for Peering into the Interior of Mice Using Intravital Microscopy

Techniques to study entire tissues, such as brain imaging microscopy, provide great insight into the biology of the whole tissue, rather than just individual cells.  Taking this one step further is intravital microscopy (IVM); a newer approach for the imaging of living tissues and organs in live animals. A wide variety of organs can be…

Variations on the ChIP-seq Theme and Challenges of Befriending Large Datasets

Variations on the ChIP-seq Theme and Challenges of Befriending Large Datasets

ChIP-seq has proved amazing. Through these new techniques, we can obtain big datasets in a matter of days, making our lives in the lab easier and more efficient. ChiP-seq combines chromatin immunoprecipitation (ChIP) assays with whole genome sequencing. This makes it possible to understand where proteins bind to DNA and epigenetic modifications. Humans are not only their…