Toluidine Blue – A Histology Stain for Mast Cells (and Other Things!)
Discover the magic of toluidine blue – a polychromatic dye that changes color depending on which tissue component it is staining.
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Discover the magic of toluidine blue – a polychromatic dye that changes color depending on which tissue component it is staining.
Just about any molecular biology experiment will involve the action of enzymes or other active proteins. And when enzymes are involved, the pH of your experimental environment is going to change. This is because most enzymatic reactions involve the loss or gain of hydrogen ions (protons), which modifies the pH of the environment. Biological systems…
Blunt-end cloning involves the ligation of DNA fragments – usually between a plasmid vector and an insert – whose terminal ends are not “sticky”. Performing these ligations is notoriously difficult, particularly with large DNA fragments. But it is possible. And in this article I’ll give you some tips that I hope will increase your chances…
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…
Get introduced to some of the special stains for histology and learn some top tips for getting great results.
If you’re picking up a list of available plasmid vectors for the first time, it can be mind-blowing to decide on the best one for your experiment. What cloning sites do you need? What restriction enzyme sites? What insert size is possible? Let me help you with some pointers about what factors to look out…
It’s 11 PM…do you know where your samples are? If you dread the thought of having to hack through ice, snow and the bone-chilling depths of every freezer to locate them, flirt with frostbite only once. Better yet, never hunt for missing lab samples again! Here are some useful ways to keep track of every…
Looking for paraffin alternatives for tissue embedding? Find out the benefits of cryo and resin tissue embedding and how they work.
The lac operon is an amazing tool in molecular biology. It has been used for decades to turn on protein expression in an inducible manner with IPTG. The result is synthesis of vast amounts of protein to be used as you wish. While the lac operon is an amazing tool for protein production, it is…
Removing proteins from acqueous solutions can be a pain if you have loads of samples to do. This article explains how to prepare the DIY phase separating gel to easily and effectively separate two-phase mixtures, saving you time and money.
This guide is full of very simple but effective tips so you can have a pleasant lab experience, and help create a happy lab.
One of the great things about being scientists is that we are lifelong learners. Scientists go to a lot of seminars, meetings and conferences. The traditional, hour-long seminar is also a great way to learn a lot in a relatively short time. So it continues to amaze me how most scientists don’t take advantage of…
Math is an important part of lab life, from making solutions to calculating protein concentrations, and miscalculations can cause mayhem for your experiments. Therefore it is important that your math is right, or you could spend weeks trying to figure out what’s going wrong in your experiments. I was hopeless at remembering how to do…
Single Nucleotide polymorphisms (SNPs), colloquially pronounced ‘snips’, are the most common type of genetic variation in people. By definition, a SNP represents a single nucleotide variation at a specific location in the genome that is found in more than 1% in the population. For example, a SNP can replace the nucleotide cytosine (C) with an…
Most of the microscopes you will encounter in your laboratories will be ‘upright’. In other words, they are assembled (from top to bottom) in the order of; eyepieces, objectives (on revolving nosepiece), stage, sub-stage condenser, diaphragm and base. However, there are two other types of light microscopes you will perhaps encounter (and use) and it…
Scientific creativity and repetitive tasks do not go well together. There is nothing worse than having to repeat the same task over and over again – I know somebody who quit science because of this and became a castle curator. So how do you minimise the amount of one of the most repetitive tasks –…
PCR has become the tool of choice for molecular diagnostics and is now a staple platform in any laboratory setting. The versatility of this method has led to a myriad of spin-off techniques, including probe-based quantitative PCR (qPCR). This method effectively combines PCR amplification and detection into a single step to measure the specific amount…
Counterstaining can have a big impact on your histology result. This short guide will introduce you to some available counterstains providing you with a few more choices.
Achieving a good immunohistochemistry signal-to-noise ratio involves many factors, including a good blocking protocol. Read on to learn about blocking non-specific staining in IHC.
Plasmid mapping and DNA annotation software is pretty abundant these days. A quick Google search brings up dozens of hits – but how do you know which one to use? If you are like most molecular biologists, you probably use the same software your colleagues do—usually it is either the stuff that gets passed down…
Following on from the first part of the H and E 101 articles, here are the materials and recipes you’ll need for your own H and E workstation (assuming you don’t have access to a histology lab). Many of the chemicals listed below are toxic and/or harmful. Use PPE when handling/storing, follow SOP’s in your…
The Irish Famine (or ‘Great Potato Famine’ if you live outside the Emerald Isle) killed one million people and forced another million to leave the country between 1845 and 1852. It was caused by a blight on the country’s main food stock- the Irish ‘Lumper’ potato. Now, researchers have identified the genome of the blight…
In the previous article, I showed you how to interpret mean-squared displacement (MSD) and showed four easy things you can learn from an MSD graph at a quick glance. Now let’s turn from analyzing an MSD plot to making one. I am going to use the programming language R to generate simulated data and then…
Haematoxylin and Eosin staining is the most common staining in the modern (and old!) histology lab. This staining technique gives an overview of the structure of the tissue and can be used in pathological diagnosis. This article follows on from Nicola’s introduction, but we’ll take an in-depth look at the stains, chemistry and method to…
I was first introduced to Conrad Waddington’s epigenetic landscape when reading ‘The epigenetic revolution’, a fantastic introduction to epigenetics, and in my opinion, a must read for anyone who is looking for an entertaining and enjoyable introduction to this fascinating field. In his model, Waddington likens the process of cellular differentiation to a marble, which…
Stuff moves. It is useful to study how stuff moves, because motion analysis can tell us a lot about the object that is moving. For example, we can learn if an object’s motion is aimless, diffusive wandering, or directed towards some goal, free to explore the available environment, or restricted to a confined space. Studying…
Developing a career in the biological sciences can be a daunting venture. You must throw your heart and soul into your career and wait years before you know if you are going to be successful. For those of you who are feeling a bit lost, I have garnered some pearls of wisdom from post-doctoral scientists…
Unlike immortalized cells lines, primary cells can only be kept in cell culture for a finite period of time, if at all. Therefore, you often need to obtain primary cells directly from an animal source. After which, you may fix and image the primary cells in situ (as part of the whole organ), or you…
Isoelectric focusing electrophoresis (IEF) of proteins is nowhere near as popular as its cousin – sodium dodecyl sulphate-polyacrylamide gel electrophoresis aka SDS-PAGE. While in both methods the proteins are denatured, IEF is a gel-based electrophoretic separation of proteins using difference in their overall charges. The sodium dodecyl sulphate – SDS part of the usual gel…
Fixing suspension cells for imaging can be trickier than fixing adherent cells, as they can’t be cultured on a coverslip. Discover how you can stick them down with the help of centrifugation.
Here are our top 10 least favorite ways to ruin that larger-than-life-sized autoclave. Don’t try these—your lab manager won’t be pleased!
Wouldn’t it be great to put your nucleotide sequence into a program and get back a 3D-structure of your protein and a full description of its functions? In theory, because the protein 3D-structure is determined by the aminoacid sequence, given the right algorithm and a powerful enough computer, this should be simple. In practice, because…
You just can’t put raw tissue or cell samples on your slides and expect good histology results! Instead you must preserve or ‘fix’ your samples. Fixing ensures that your cell structures stay intact and that your antigens are immobilized. Ideally, fixation would also still permit unfettered access of your antibodies to your antigens. However, as…
According to the central dogma of molecular biology, DNA is transcribed into RNA, that is translated to proteins. Inconveniently, the vast majority of the genome contains sequences that do not actually code for proteins. So, this non-coding RNA (ncRNA) was dismissed as non-functional junk, letting researchers tick the box on their to-do lists and head off…
Most of us have had to write a lay summary or abstract at some point. How easy do you find this? In my experience, it is harder than you think! Whether for your thesis, graduate fellowship grant application, or even lab newsletter, writing about your research in plain English is a crucial skill. Communicating your…
The theory behind the idea of having shared microscopes is a good one, but, in reality, this can sometimes mean you have to put up with the dirty habits of your fellow scientists and researchers. And some of your lab mates turn out to be really mucky! Here’s my Top 10 of things which really…
The conventional sequence for getting a new job in science (or anywhere else) goes like this: 1) Apply for a job 2) Get an interview 3) Ace the interview 4) Pray that your references hold up. So if you had a bad relationship with your last boss, you’re in trouble. Because no matter how well…
Recently BsB author Yevgeniy Grigoryev shared a total RNA isolation protocol. The one I use is even simpler—no expensive Trizol, which is a mix of phenol and some salts, all that is required is some Tris, SDS and phenol/chloroform mix. I have never used this protocol on non-yeast cells but I am almost sure that…
It is the black death of cell culture. Scientists don’t dare utter its name and many a graduate student has fallen victim to its indiscriminate menace. These stealthy anarchists infiltrate quietly but deliberately until their numbers swell and then they attack in strength, overwhelming their victims before they can put up a fight! What is…
Have you ever emerged from the lab, bleary-eyed, blinking dazedly at the sun after spending hours hunched over a lab bench counting endless bacterial colonies or viral plaques? A necessary evil… I consider colony/plaque counting one of the necessary evils of working with microorganisms. Necessary because many experiments have an endpoint that requires determining the…

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