Nodulation: What Is It and Why Is It Important?

Nodulation: What Is It and Why Is It Important?

Plants are incredibly organisms. Not only do they provide atmospheric oxygen, but, in the case of legumes, they can transform atmospheric nitrogen gas to ammonia, which can then be consumed by humans. How does this happen, you ask? It’s all thanks to bacteria and the process of nodulation. Deep Breaths Nitrogen is an incredibly important…

Successful Start: Tips for Establishing Organoids

Successful Start: Tips for Establishing Organoids

Organoids are a developing star of research. They can be grown to represent the majority of mammalian organs and have a wide range of possible applications. More realistic than simple monolayer cell culture, they offer an in-between step that reduces the need for animal models and simplifies (although doesn’t completely remove) ethics paperwork. They are…

dry vs wet

Should You Switch from Wet to Dried Blood Samples?

A Spot of History Most of the biomedical methods used started as a curiosity. Then the one-off gains a limited use, the technology then progresses until its use becomes widespread. Just think about the arch from the curious polished glass spheres, used by Antony Levnhook to look at animalcules, to modern microscopes. The same story…

Icky Sticky: Heat Shock Protein Contamination during Protein Purification

Icky Sticky: Heat Shock Protein Contamination during Protein Purification

Purifying a new protein is no easy feat. Finding combinations of protein purification buffer, salt, detergent, and stabilizing agent to get high yields of squeaky-clean protein can become tedious. Few things are as bothersome during this process as Heat Shock Protein (HSP) contamination. But worry not, we’ve got some handy tips to avoid HSP contamination…

DNA size selection for NGS libraries
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DNA Extraction for Next Gen Sequencing

The advent of Next Gen Sequencing (NGS) has been truly amazing. One of the marvels that is often overlooked is how advances in DNA extraction technology have helped streamline NGS workflows. The original standard – phenol/chloroform extraction – is not well suited to the automated nature of today’s sequencing workflows (though with the emergence of…

Faster Ligations: PEGing down the Secret

Overnight ligations are inconvenient — especially when they fail. Luckily, there’s a straightforward way to faster DNA ligations. This article highlights the secret ingredient to faster ligation reactions and offers some tips and caveats on its use. For a general overview of DNA ligations, see here and here. Buy a Quick Ligation Kit The most…

Spinning Around: Tips and Tricks for Using Centrifugal Filters

Spinning Around: Tips and Tricks for Using Centrifugal Filters

One of the most widespread protein laboratory accessories are the MWCO (molecular weight cut-off) centrifugal filters which are commonly used for concentrating protein, as well as DNA. They are available commercially with different cut-offs including 3kDa, 30kDa, 50kDa, 100kDa, and so on. These little devices are expensive and hence demand proper usage and care to…

Staying Alive: Tips for Air-Liquid Interface Cultures

Staying Alive: Tips for Air-Liquid Interface Cultures

What Is Air-Liquid Interface Culture? Long gone are the days where scientists had to rely on 2D cultures of immortalized cell lines to learn principles of human biology. Today, we have a variety of cell culture systems that come closer than ever before to mimicking the structure and function of our body’s organs. One example…

Getting Sensitive: Diagnostic Sensitivity and Specificity Simplified

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…

Mouse lightbulb

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…

How Strong is Your Binding? A Quick Introduction to Isothermal Titration Calorimetry

How Strong is Your Binding? A Quick Introduction to Isothermal Titration Calorimetry

What is Isothermal Titration Calorimetry? Isothermal titration calorimetry (ITC) measures the heat generated (or absorbed) when one solution is titrated into another. Most commonly, a small molecule or peptide is titrated into a protein. If the molecule binds to the protein, heat is given off (or absorbed) with each injection, until the protein is saturated.1…

Library Prep

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…

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

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

If you look at the composition of peripheral blood, using hematology microscopy, you’ll see that it’s composed of multiple different cell types, including monocytes. It’s possible to isolate these different components to study and experiment on them directly. So, if you’ve done a few experiments and had fun with THP-1 cells, you can move on…

Culturing the Unculturable: Working with Difficult Bacteria

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…

CPEC– a Quick and Inexpensive Cloning Strategy

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…

DNA barcoding

What’s that Organism? Using DNA Barcoding for Species Identification

In both the lab and field, it is important to know what species we are working with. While morphological data has always been a tried and true method of identifying species, DNA barcoding allows us to identify species when we don’t have that option (e.g. if we don’t have enough of a specimen to identify…

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

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…

Use ddRAD-seq to Study Non-Model Organisms
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Use ddRAD-seq to Study Non-Model Organisms

Reduced-representation genome sequencing has been one of the most important advances in the last several years for enabling massively parallel genotyping of organisms for which there is no reference-grade genome assembly. An implementation of the approach known as ddRAD-seq, first conceived in the Hoekstra lab at Harvard, has been widely adopted by the plant and…

An Invisible Bug Ate My Experiment:  What to Do about Greenhouse Infestation

An Invisible Bug Ate My Experiment: What to Do about Greenhouse Infestation

In theory, the greenhouse is a controlled laboratory environment where only the organisms you’ve introduced live. But in practice, just as other laboratory environments suffer from ‘unwelcomed guests’ (e.g. contamination and infestation), greenhouses are not always as sterile as you would like. To avoid any experimental issues, you have to be vigilant about these pesky…

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Reducing GC Bias in WGS: Moving Beyond PCR

WGS technologies have seen significant progress since the completion of the Human Genome Project in 2003. First-generation Sanger Sequencers were limited by lengthy run times, high expenses, and throughputs that read only tens of kilobases per run. The arrival of second-generation sequencers in the mid-2000s brought about the plummeting of sequencing costs and run times,…

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NGS 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…