“Viable But Non-Culturable (VBNC)”: Zombies of the Bacterial World

“Viable But Non-Culturable (VBNC)”: Zombies of the Bacterial World

Imagine that you want to test the efficiency of an antimicrobial treatment in inhibiting a certain bacterial pathogen. As part of the experiment, you expose the bacteria to the treatment and monitor the cultivability of the microorganism by counting the number of colony forming units (CFU) formed on culture media. If the microorganism is sensitive…

Ten Tips for Pipetting the 384-Well Plate

Ten Tips for Pipetting the 384-Well Plate

I was so excited to start using 384-well plates for my assays. With so many wells, these plates are useful for testing many conditions in parallel, as required in ELISAs, siRNA library screens, and drug treatment dilutions. However, I quickly learned that pipetting in these plates is more complicated than I thought. This article contains…

The qRT-rtPCR Control You Should Be Doing, But Probably Aren’t

The qRT-rtPCR Control You Should Be Doing, But Probably Aren’t

Every man, woman, and dog is doing quantitative real time reverse transcriptase PCR (qRT-rtPCR) these days. It’s a great method to measure your favorite transcript’s expression levels. One of the big plusses (like the Swiss flag!) of quantitative PCR in general is its high sensitivity. In principle, it can detect and quantify one molecule of…

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…

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…

How to Choose the Correct Reverse Transcription 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…

Reverse Transcription: The Most Common Pitfalls!

Reverse Transcription: The Most Common Pitfalls!

Good quality starting material is king for reverse transcription! Obtaining reliable results in any experiment requires good preparation. We often take reverse transcription for granted, and we don’t always consider that our qPCR might be performing poorly because of problems in that step. Since it’s quite often the reverse transcription reaction itself that causes fuss…

From Revolution to Evolution: Stem-loop Real-time PCR

From Revolution to Evolution: Stem-loop Real-time PCR

Kary Mullis invented polymerase chain reaction (PCR) in 1985 creating a revolution in molecular biology techniques. But it hasn’t stopped there. PCR has greatly evolved over the years. Today, we stand at a point, where we can clone micro RNAs (miRNAs) in real time! Due to miRNA size (about 18-21 nucleotides long) and varied expression levels,…

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….

10 Tips for Consistent qPCR

10 Tips for Consistent qPCR

Quantitative PCR (qPCR) uses fluorescent dyes or probes to visualize the amplification of specific DNA sequences as it happens (i.e. in real time). The dyes or probes fluoresce when they bind to newly amplified DNA, and the amount of fluorescence emitted is proportional to the amount of DNA (or mRNA) present in the original sample. By detecting newly synthesized DNA…

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…

Detecting Signal in qPCR: From DNA Binding Dyes to BHQ Probes
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Detecting Signal in qPCR: From DNA Binding Dyes to BHQ Probes

A Brief History of Detecting Amplicons The Old Days of Ethidium Bromide In the early 1990s, quantitative (q) PCR was in its infancy, and despite PCR itself already being around for 10 years, there were no easy ways of precisely quantifying the amount of DNA that was amplified in a PCR reaction. In those days PCR…

Finding Nemo: Understanding Single Cell Isolation and PCR Amplification

Finding Nemo: Understanding Single Cell Isolation and PCR Amplification

Every protocol for single cell PCR can be broken down into two steps. In the first step, the cells are isolated by micromanipulation, laser capture microdissection, flow cytometry, or by direct micropipetting. Next, the genetic material is processed by PCR to amplify your sequence of interest. Here, we’ll go through the different options for isolating…

Mediator Probe PCR

Mediator Probe PCR

Want a PCR method that gives you high sensitivity and is cost-effective? Then you might want to try Mediator Probe PCR.  This method gives you sensitivity and limit of detection comparable to that of dual-labeled hydrolysis probes without the high cost. We all know how expensive small batch probe synthesis orders can be, especially when…

Polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA)

Polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA)

As researchers, we are constantly on the lookout for new and improved ways to analyze, detect and quantify our favorite protein or gene. Luckily, we don’t always need to reinvent the wheel! PCR-ELISA is a good example of where two commonly used techniques have been merged together to create a very powerful analytical tool. What…

The History of PCR

The History of PCR

As with some of the greatest discoveries in science, from penicillin to microwave ovens and play-doh, PCR was discovered serendipitously. Thanks to the work of many scientists, including Watson and Crick, Kornberg, Khorana, Klenow, Kleppe (so many K’s…) and Sanger, all the main ingredients for PCR had been described by 1980. Like butter, flour, eggs,…

The Devil is in the Details: How to Setup a PCR Laboratory

The Devil is in the Details: How to Setup a PCR Laboratory

There is a right way and a wrong way to set up a PCR laboratory. Because of PCR’s tremendous ability to amplify small quantities of DNA/RNA template, even the smallest of template contamination can become a huge problem in PCR. However, contamination does not have to be a problem in your laboratory. Read below to…

Do-it-Yourself PCR

Do-it-Yourself PCR

Currently Open Source principles are offering interesting tools for doing molecular biology at an incredibly low cost. One interesting example is OpenPCR (www.openPCR.org) a project developed in order to ensure that the basic technology to perform PCR is affordably and openly available to all. In the past one of the main barriers for introducing PCR technology…

The different Phases of PCR and Why They Are Important

The different Phases of PCR and Why They Are Important

PCR (Polymerase Chain Reaction) is a biochemical technique developed by Kary Mullis in 1983 that is used to create large quantities of a sequence of DNA. Since this method of mass-producing DNA was first introduced, it has become significantly less labour intensive, more economical, and more routine. The technique relies on a few key players…

Digital PCR or Quantitative Real-Time PCR: Which Method Is Best for Your Quantitative PCR Application?

Digital PCR or Quantitative Real-Time PCR: Which Method Is Best for Your Quantitative PCR Application?

So you’re designing a new experiment that requires PCR quantification. You used to have only one method to choose from, but now you have two – Quantitative Real-Time PCR (qPCR) and Digital PCR (dPCR). Which one is right for your application? Both methods have good quantification, sensitivity and specificity for most applications. They are compatible…

Western Blot, ELISA, SPR, Biosensor Assay or PCR: Which Technique Should I Use?
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Western Blot, ELISA, SPR, Biosensor Assay or PCR: Which Technique Should I Use?

Stimulation of cells/tissue with a given stimulus (e.g., a cytokine) is a common experimental setup in any cell biology lab. The cellular response to the external stimulus e.g., the activation/deactivation of intracellular signaling pathways and/or the secretion of proteins is often the research goal, and there are a number of different methods that you can use to analyze such…

Apps That Bring PCR to Your Mobile Device

Mobile devices such as iPads and smartphones are increasingly being used by laboratory researchers to aid them in their research. One example is the move towards electronic lab books. As a result, app developers have responded to this trend and are developing apps tailored to specific laboratory techniques including PCR and qPCR. The following are…

How to Train a Junior Colleague in the Basics of PCR

How to Train a Junior Colleague in the Basics of PCR

You’re a senior grad student or postdoc, and you’ve done more PCRs than you can count. A new student has joined your lab, and you’ve been charged with training them on PCR. You don’t want to lead him/her astray, but it’s hard to remember the parts that you struggled with in your early days. This…

How RNA-FISH Can Complement qPCR, and Vice Versa
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How RNA-FISH Can Complement qPCR, and Vice Versa

In studies of RNA abundance and gene expression, no one technique can answer all of the questions that need to be asked. So it is necessary to use a variety of experimental methods in concert. Two RNA detection and measurement techniques that complement each other well for this purpose are RNA Fluorescence in situ hybridization…