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Techniques

Laemmli Buffer: What Is It for Anyway?

Electrophoresis encompasses a wide range of techniques in which charged biomolecules in a liquid, a solid, or a semisolid solution can be separated by size under the application of an electric field. The most common application of electrophoresis for the separation of proteins is SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis), which has been previously covered here.  …

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Getting Sensitive: Diagnostic Sensitivity and Specificity Simplified

What Do We Mean by Diagnostic Sensitivity? In clinical diagnostics, questions about the sensitivity of an assay will inevitably surface. But what does “sensitivity” mean exactly? The lowest quantity of the given analyte that an assay can detect is often called sensitivity – and to be clear, this quantity is the analytical sensitivity or Limit…

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Designing a LOV2 Domain-Based Toolkit

Cell Biology is entering the Age of Light with a spectrum of new optogenetics tools available to control protein function using light. Once the remit of neuroscientists [1], the past decade has yielded a bounty of novel light-controllable domains that are now being leveraged to illuminate the dark corners of basic cell biology [2,3]. The…

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C. elegans: The Elegant Model System

In research, choosing a model system is like choosing a partner – you want it to be a perfect fit. If you are attempting to solve problems such as finding unknown proteins in known processes, investigating unknown functions of known proteins or correlating cell biology to a function for which you want a relatively simple…

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Five Factors Affecting Your Mouse Behavioral Studies 

Let’s face it: the nature of behavior itself is inherently variable, whether it’s the heterogeneous socializing behavior of humans at parties, the complex aggressive behavior of rodents when they perceive a threat, or the intricate courtship behavior of insects during their mating dances. Because of this variability, the struggles associated with trying to (successfully) reproduce…

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Controls for Immunofluorescence: A Beginner’s Guide 

Immunofluorescence staining is a popular and extremely powerful detection method. However, achieving publication quality immunofluorescence or fluorescent antibody staining can get tricky. It’s therefore important to ensure you have the right controls for immunofluorescence.   Since immunofluorescence staining is a long process with many steps, it is always advisable to spend some time optimizing each…

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How to Prevent False Results in Colony PCR

How to Prevent False Results in Colony PCR Colony PCR saves time and reduces costs by eliminating the need for plasmid purification. However, confounding results abound — but only if you fail to anticipate them. This article outlines the major perpetrators of false results and how to prevent them. For a more general overview of…

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How to Set up Your Elution Experiment

What do DNA mini preps and protein immunoprecipitation experiments have in common? They start differently, but they end with the same, critical stage – elution. But what exactly is elution, and what is the point? The Terminology First, let’s start with some basic terminology: Elution – extracting one material from another by washing with a…

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Get Prepped: Nanopore Library Preparation Optimization

Nanopore is a relatively new sequencing platform and researchers are still trying to optimize the protocol for their own specific applications. In our lab, we work primarily with metagenomic samples and use the 1D sequencing kits. Over the past year, we have optimized this technique. To check the quality of the Nanopore library preparation we…

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A Bug Ate My Experiment, Part 2

In the first article of this series, I introduced microscopic parasites that infect greenhouse plants.  Initially, my goal for Part 2 was to list all the main types of infestations, but I quickly realized to do so would result in a textbook. Thus, this article will be about the most familiar and easy to identify…

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Isolating Monocytes from Whole Blood: A Step-by-Step Guide

So, you’ve done a few experiments and had fun with THP-1 cells, but now it’s time to translate those results to primary human monocytes. Isolating monocytes requires blood. Lots and lots of blood, depending on your downstream assay of choice. The yield can vary wildly by donor (if they had a cold at the time…

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CRISPR-Based Activation (CRISPRa) of Genes: A How-To Guide

The purpose of this article is to walk you through the steps needed to overexpress genes using CRISPR/Cas9-based activation (CRISPRa). A broader overview of this topic (including CRISPR-based repression) can be found here. CRISPR/Cas9 is more than a programmable nuclease. When stripped of its nuclease activity, it can activate and repress transcription, alter chromatin structure,…

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Culturing the Unculturable: Working with Difficult Bacteria

As the vast majority of bacteria cannot be readily cultured in the laboratory [1], culture-dependent methods to investigate bacteria grossly underestimate the diversity of bacterial communities. To investigate unculturable bacteria without isolating them, culture-independent methods such as sequencing have been used. Unculturable bacteria can be identified by PCR amplification and sequencing of housekeeping genes such…

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CRISPR-Cas9 Genome Editing: Weighing the Pros and Cons

Genome editing is a hugely powerful tool which can help you to address a multitude of questions in your research. However, it is not necessarily the best tool for the job in every situation. Below is a discussion of the main advantages and disadvantages associated using CRISPR-Cas9 for genome editing. The Pros It’s Simple to…

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CPEC– a Quick and Inexpensive Cloning Strategy

Cloning Strategies – a Whole Lot of Options to Choose Molecular cloning has come a long way from simple restriction digestion-ligation cloning strategies to a large number of highly efficient alternatives. Broadly classified, cloning techniques can be divided as sequence dependent and sequence independent strategies. Sequence-dependent strategies are based on restriction digestion-ligation techniques or site-specific…

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How to Transform Microalgae

What is the first image which comes to mind when you think about microalgae? Green scum that covers the surfaces of ponds? Unsightly stains on pavements and walls? Far from being a nuisance in ponds, lakes, drains and on surfaces, microalgae are fascinating microorganisms which are used to understand various biological processes. Microalgae have been…

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So You Think You Can PEMSA? A Guide to Protein Electrophoretic Mobility Shift Assay

Studying nucleic acid interactions with proteins can be accomplished using a rapid and efficient electrophoretic mobility shift assay (EMSA). This method is essentially an agarose gel electrophoresis technique that detects protein:nucleic acid interactions, as the mobility of the labeled nucleic acid will be retarded if bound to a protein (compared to unbound DNA). A lesser-known…

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