Troublesome Site-Directed Mutagenesis: Troubleshooting Your Experiment for Stubborn Mutations

Troublesome Site-Directed Mutagenesis: Troubleshooting Your Experiment for Stubborn Mutations

As is sadly the case in many experiments, site-directed mutagenesis (SDM) does not always work the way we would like it to the first time around. Here are a few tips to help you on your way when trying to troubleshoot a bothersome SDM reaction!

Immuno-PCR:  A Highly Sensitive Method of Immunodetection

Immuno-PCR: A Highly Sensitive Method of Immunodetection

Researchers have relied on immunodetection techniques such as Western blotting, flow cytometry and Enzyme-Linked Immunosorbent Assay (ELISA) for years, but immuno-PCR is a relatively new method. By merging an ELISA with the Polymerase Chain Reaction (PCR), immuno-PCR provides extremely high levels of assay sensitivity. ELISA An ELISA is an assay in which a molecule is…

Primer Validation Was a No-Go – Now What?

Primer Validation Was a No-Go – Now What?

The primers for your gene of interest have finally arrived in the mail, and you’re ready to figure out whether your favorite gene’s expression level is elevated in those precious tissue samples. Only one small last step before you can proceed. Primer validation. This is a standard procedure where you run PCR or qPCR on…

Quantifying Allele-Specific Gene Expression Using PCR-Based Methods

Quantifying Allele-Specific Gene Expression Using PCR-Based Methods

Allele-specific expression can occur for various biological reasons, such as gene imprinting, or differential transcription caused by mutations, or single nucleotide polymorphisms (SNPs), or epigenetic alterations. Traditional end-point RT-PCR or qRT-PCR-based methods only detect overall levels of mRNA expression from a given gene rather than mRNA transcripts originating from individuals. If your project requires more…

Intercalating Dyes or Fluorescent Probes For RT-qPCR?

Intercalating Dyes or Fluorescent Probes For RT-qPCR?

The unique feature of real-time quantitative polymerase chain reaction (RT-qPCR) is that it associates the amplification of your target gene with a fluorescent signal in a quantifiable manner. Presently, there are numerous fluorescent tool kits/methods to consider when designing your RT-qPCR experiment. However, the two major categories to choose from are fluorescent intercalating dyes and…

Oligo Purification Methods: How, Why and for What?

Oligo Purification Methods: How, Why and for What?

Who amongst us hasn’t had the need for oligonucleotides in an experiment? It is a cornerstone in many procedures and techniques. Depending on the goal, it can be very hard to design just the right oligo for your experiment.  Oligos must have the right length; the right amount of C-G, T-A; they can’t form secondary…

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…

Get Your Polymerase Cycling Assembly Oligos Together

Get 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…

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

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…

A Primer on Checking the Methylation State of the Genome

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…

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…

Faster PCR Optimization

Faster PCR Optimization

So, you’ve designed PCR primers to amplify your sequence of interest, and you’re ready to go.  But unless you have a never-ending supply of template, polymerase, and a thermocycler with a gradient function—not to mention a hefty dose of time and patience—you probably don’t want to spend the next week finding the perfect conditions for…

SPUD’s Your Bud When it Comes to Sensitive qPCR

SPUD’s Your Bud When it Comes to Sensitive qPCR

There’s piloting a brand new technique for the first time. Then, there’s jumping through hoops trying to get an established lab technique to work. The former, in contrast to the latter, is expected to be fraught with hardships. Yet troubleshooting an old lab technique that isn’t working anymore, is frustrating at a whole new level….

There’s No Need To Be Paranoid About RNA Purification
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There’s No Need To Be Paranoid About RNA Purification

RNA purification may be a common procedure in molecular biology but it is by far the one that people fear most. Why? Dreaded RNase. It’s everywhere… all over your bench and pipettes, and floating in the air, waiting for the chance to creep into your prep, shred your RNA into nucleotides, and ruin a day’s…

How to Cheat QuikChange™
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How to Cheat QuikChange™

Generating a DNA vector library of single and/or compound mutants for a target protein can be a daunting task. If you’re lucky and work in a well-funded lab, you might outsource this process via gene synthesis. Most of us though, need to do it the old-fashioned way. Traditional QuikChange™ Traditionally, there are many steps you…

Long-Range PCR:  It’s About Choosing the Right Enzyme

Long-Range PCR: It’s About Choosing the Right Enzyme

The ability for DNA polymerase to copy a long stretch of DNA is becoming increasingly important. Why? It has to do with the advances in our sequencing technologies. Our next generation sequencing (NGS) technology requires the DNA polymerase to copy a long stretch of DNA (sometimes up to 50kb) as NGS is churning out genetic…

Photonic PCR: When Lightening Strikes Your DNA

Photonic PCR: When Lightening Strikes Your DNA

Before I get into today’s topic, please allow me to digress a bit and start with a few sentences that sum up the polymerase chain reaction (PCR); the grand-daddy of molecular biology. PCR, a method that is at the heart of modern day molecular biology discoveries, is a process that amplifies genetic material through our…

Time to Instigate Nested PCR

Time to Instigate Nested PCR

How to Obtain a Purer PCR Product and Reduce Non-specific Amplification Unless you’ve gotten your hands on some miraculously specific primers, amplification of only your target sequence without non-specific amplification can be very challenging. Thankfully, a clever and surprisingly simple solution is at hand! A Quick Recap of the Basics In PCR, you design your…

Designing Luck: 8 Basic Concepts for Designing Primers for a Standard PCR

Designing Luck: 8 Basic Concepts for Designing Primers for a Standard PCR

I think we all have been through those my-PCR-product-didn’t-get-amplified days. Sometimes, playing around a bit more with the PCR conditions brings luck, or sometimes it doesn’t work at all. These days we have access to many different types of DNA polymerases, ultrapure and buffered nucleoside triphosphates, and other necessary starting materials in convenient concentrations; but…

Polymerase Incomplete Primer Extension (PIPE) Cloning Method

Polymerase Incomplete Primer Extension (PIPE) Cloning Method

PIPE PCR is a ligase-independent, restriction enzyme-free cloning strategy like SLIC (link to my SLIC article), SLiCE and CPEC. The PIPE method eliminates sequence constraints and reduces cloning and site mutagenesis to a single PCR step followed by product treatment. It is fast, cost-effective and highly efficient. The key step is designing the primers; one…

How to Be Greener – The Environmentally Friendly Guide to PCR

How to Be Greener – The Environmentally Friendly Guide to PCR

Science is an expensive business and those who use high energy-demanding techniques may not even realize just how expensive they are. The Cost of PCR Let’s looks at PCR. You need to pay for the machine, all the ingredients including expensive enzymes, a freezer and a fridge for your ingredients, tubes and caps, not to…

Modify Your Oligos, Modify Your Experiments
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Modify Your Oligos, Modify Your Experiments

If you’ve ever performed PCR, you’re probably already very familiar with DNA oligonucleotides (or oligos). But did you know that these molecules can do so much more than just act as simple primers? You can add a wide range of modifications to your oligos, which may change the stability, binding, solubility and even visibility, to…