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Search below to delve into the Bitesize Bio archive. Here, you’ll find over two decades of the best articles, live events, podcasts, and resources, created by real experts and passionate mentors, to help you improve as a bioscientist. Whether you’re looking to learn something new or dig deep into a topic, you’ll find trustworthy, human-crafted content that’s ready to inspire and guide you.
Brightfield Illumination This defines the most basic method of optical microscopy using white light to illuminate the sample in the transmitted mode. Absorption and diffraction of the light by the molecules in the specimen generates the contrast in the image. Methods such as darkfield illumination, differential interference contrast and phase contrast help to increase the…
Collecting biological samples in the field can be difficult, since storage conditions outside of the lab are often less than optimal. Enter the Whatman FTA (Flinders Technology Associates) Cards. The Whatman FTA Card, a filter paper product manufactured by GE Health Care, is a paper matrix laced with a proprietary mixture of chemicals that lyse…
During my postgraduate studies, I did literally one PCR reaction with a pre-optimised protocol on a not especially difficult template. So my karma came back with vengeance, when as a part of my first postdoc I had to amplify a template containing a 35 bp-long GC-rich stem-loop, which proved to be extremely difficult. This was…
A revolution in 2005 The start of the NGS revolution was clearly marked in 2005 by the publication of the complete genome sequences of two bacterium (Mycoplasma genitalium and Streptococcus pneumonia) by 454 Life Sciences Corporation in one run of their Genome Sequencer with a 96% coverage at 99.96 % accuracy (Margulies et al. 2005)….
Have You Tried Trichrome? The trichrome stain is one of the most commonly used special stains in every histology lab. The pedantic meaning of the word trichrome is “three-coloured”, referring to how the technique differentially stains tissue samples in three colors. However, the term is now actually used to describe any staining method using two…
Just before Life Technologies purchased the start-up company Ion Torrent, the fledgling company was dealing with a torrent of another kind—worldwide media interest in its new sequencing technology, which promised to bring the price of next-generation, massively parallel sequencing down to $1,000 per run. Since that dramatic announcement in the summer of 2011, Life Technologies…
Mammalian cell transfection is a technique commonly used to express exogenous DNA or RNA in a host cell line (for example, for generating RNAi probes). There are many different ways to transfect mammalian cells, depending on the cell line characteristics, desired effect, and downstream applications. In this article, I will review the different methods of…
Why confocal? The standard fluorescence widefield microscope described in our last article has one major disadvantage: it collects not only the desired image information from the focal plane, but it also records a large amount of out-of-focus light, leading to a blurred image. In the 1950’s, system developers started thinking about how to get rid…
The “sequencing-by-synthesis” technology now used by Illumina was originally developed by Shankar Balasubramanian and David Klenerman at the University of Cambridge. They founded the company Solexa in 1998 to commercialize their sequencing method. Illumina went on to purchase Solexa in 2007 and has built upon, and rapidly improved the original technology. Millions of reactions and…
Arguably, molecular biology is impossible without microbiology—even if you work exclusively with transgenic mice, you may one day need to amplify a vector in E. coli. And microbiology is definitely impossible without good aseptic technique. The main principle of good microbiological practice is a zero tolerance approach: it’s good to be a little paranoid about…
Think before you start! Before you even start preparing your samples, you should think about the choice of microscope for image acquisition. Manufacturers offer an ever increasing range of light microscopes- some of which may already be available in your research institutes. To help you get the best out of your imaging experiment by making the…
Don’t be left in the dark! Navigating through the sea of parameters that can aid or abet successful microscopy can perhaps seem daunting. It may be tempting to assume you can just sit down at a microscope, look at your sample, and obtain beautiful images simply by hoping for the best. However, even a basic…
Much more than just an archive, The Cell: An Image Library-CCDB (Cell Centered Database; ‘The Cell’) serves many additional purposes. Whilst many researchers use The Cell to organize their own images for research and archival purposes- the real value of The Cell is the ability to share those images with other researchers. In many scientific…
Protein tags are invaluable tools for the modern biologist, particularly if you work on one of the 99% of proteins for which there isn’t a nice antibody readily available. If you want to purify large amounts of your protein of interest, detect it by western blot or fluorescence microscopy, or identify its potential binding partners,…
Next Generation DNA Sequencing (NGS) is a revolutionary new technology that provides biologists and medical scientists with the ability to collect massive amounts of DNA sequence data both rapidly and cheaply. This technology is having a huge impact on many aspects of biology and medicine because it can be applied in so many different ways….
It’s unclear exactly how the term ‘Special Stains’ first arose in the world of histology, but it refers to empirical and histochemical staining techniques that significantly contributed to the advancement of histology in the late 19th century. In a nutshell, these stains are ‘Special’ because they are not routine – simple as that. Therefore, Special…
Mycoplasmas are the most difficult-to-detect organisms in your eukaryotic cell culture. And they can be the most dangerous; they can disrupt cell growth and differentiation and even apoptotic patterns without you even knowing what’s going on until it’s too late. Traditional cell culture methods can take up to a month to yield results, which means…
In a typical biology lab, you may encounter many types of biological materials, including cells, bodily fluids, purified DNA and RNA, enzymes, bacterial cultures, body parts, and whole animals. In order to perform experiments that yield quality results, samples need to be stored properly in order to preserve their activity or integrity. Beginning students and…
You’ve spent days, perhaps weeks or months squirrelling away tubes of preserved tissue in the dark drawers under your laboratory bench like the trophies of a demented serial-killer. Hours have been spent in histology in the processing, embedding and sectioning onto slides. Finally, like a warrior victorious in battle, you hold aloft your thin glass…
Here, we share a protocol for a midiprep, which, if not faster, gives a larger plasmid DNA yield than any commercial midiprep kit.
Summertime… The birds are singing, the trees are growing. Your tissue culture has sprouted yeast contamination, your yeast culture is happily growing bacteria. Your bacterial culture was growing calmly and predictably, dividing every twenty minutes, but suddenly its optical density has dropped, and it’s full of some sort of filaments and clumps. Or you did…
Before using any Biological Safety Cabinet (BSC) for the first time, have a person with working knowledge of the machine give you an overview of how to use the cabinet. Different labs have different protocols in regards to running the cabinet, disinfecting the cabinet, determining which pathogens that may be used in the cabinet and…
The last step in western blotting is imaging the blot – this is the moment of truth, when you finally get to see the results of the experiment you’ve been working on for so long! There are a variety of different ways to image your blot. The method you choose will largely depend on the…
As we learned in my previous article, cell culture hoods have many names. As if that wasn’t enough, they are all-too-often misunderstood and mistreated, which can lead to dangerous situations harmful for both the worker and the general lab environment. Here are three common ways that workers abuse biological safety cabinets; make sure you don’t…
Biological safety cabinets, laminar flow hoods, clean hoods and culture hoods are all common names for those essential pieces of equipment that you use in cell culturing. The terms are used inter-changeably, but in fact there are lots of different types of culture hoods, each of which does a different job. Knowing which is which…
The first step in most Western blotting experiments is lysing your cells to extract protein. You need to break open your cells in order to be able to isolate the proteins, and you need to do this with the least degradation and the most reproducibility possible. Depending on what your starting material is, there are…
There are several yeast transformation protocols around, and most of them require a lot of steps: overnight starter culture, dilution and growth to logarithmic phase, several washes, and so on… These protocols work very well since they have been optimised for maximum transformation efficiency, which is needed for applications like library construction. But they are…
Proteases: wild, mysterious, destructive. What are these untamed elements ravaging your precious lysate? How can a drop of EDTA or a smidge of “cocktail” protect that sample, which is gently cradling your hopes, your dreams, and your desire to survive the next lab meeting? Brace yourself for a biochem flashback: in this article, we’ll explain…
After having discussed what epigenetic mechanisms are and how we’ve learnt about what they do, it is now time to look into how epigenetics affect our lives if things do not go the way they are supposed to go. I hope I have convinced you that epigenetic processes are vital for an organism, in development…
Epigenetics is the most rapidly expanding field in biology. In the second article in this series, I discussed which experimental techniques have been crucial in gaining insight into epigenetic processes. I will now shed light on what those and other methods have taught us. As described in the first article, it has been long understood…
In the past decade, important advances have been made in the field of epigenetics. Obviously, unraveling epigenetic mechanisms has been greatly facilitated by technological developments. I’ll try to give you an impression of the types of experiments that have helped fuel those new and exciting insights. Yevgeniy Grigoryev has recently written an article on DNA…
These days, epigenetics is a fast moving field. I don’t remember having learnt about it during my biomedical studies, some 10 years ago. Nowadays, there seems to be no way around it when studying health and disease. Increasing interest combined with recent technological breakthroughs have led to quickly expanding knowledge of its abundant and important…
A young laboratory technician was puzzled by his plates when he pulled them out of the warm room. They never looked that cloudy and fuzzy before. He brought them to his lab director, who shook her head sadly; together, they threw the plates away. Does this story sound familiar? What probably happened was an all-too…
Mycoplasma infections are very, very bad news; these special prokaryotes can rapidly spread through your cell culture and inhibit cell proliferation, induce apoptosis, cytokines and radicals, and otherwise transform your cells. Worst of all, since contamination is not easy to spot, you may not realize your culture is contaminated until it’s too late. The 100…
Commercial kits for isolation of large quantities of plasmid DNA generally rely on standard alkaline lysis followed by an affinity chromatography column-based method to purify DNA. Compared to traditional cesium chloride banding or PEG precipitation of plasmid DNA they are a breeze, and have the added benefit of avoiding use of toxic or hazardous chemicals…
Western blots may be great for visualizing protein expression, but they can be a perfect way to waste your precious antibody stocks if you follow the normal protocol. Thankfully, you don’t have to follow the normal protocol any more; here’s how to get great blots with a fraction of the antibody usage. I have tried…
You’ve masterfully run and transferred your gel, and now it’s time to probe and quantify your protein(s). You’ve got your antibodies and ECL ready to go. Substrate – check. Film cartridge – check. Darkroom – ah yes, that magical place where night vision goggles are required to navigate a veritable minefield of potential chaos. It…
Epigenetics is the study of heritable changes in the phenotype of a cell or an organism that are not encoded by the genome (hence epi which means ‘above’ in Greek, and genetikos which means ‘origin’). In this article, we’ll discuss DNA methylation, a common epigenetic modification: what it is, how to detect it, and how…
When running a quantitative Western blot, it’s crucial that your sample preparation is consistent. Incomplete protein extraction from one sample will skew your results when you compare it to the protein content of a sample that was extracted more thoroughly. And after the protein extraction, it’s important to handle the samples in an identical manner…
Working with RNA? What fun! Those little, nearly indestructible RNases are everywhere – on your skin and mucous membranes, in the water and (some of the) enzymes you use, on lab surfaces, even in airborne microbes! Here are 10 ways to keep the RNases at bay, and keep your precious samples safe:
Technique, tips, ergonomics, and ISO guidance all in one handbook
