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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.
Now we come to the third part of our trifecta; in the last two posts I have gone over p-values and how they determine significance in null hypothesis testing, and we talked about degrees of freedom and their effect on the p-value. Finally, we come to pseudoreplication: where it can all go terribly wrong. Replication…
In the previous article in this series, we covered teamwork and networking. Now it’s time to move on to what many people consider the most boring part of the lab work: the analysis. I know we all wish that a simple histogram or a rather nice-looking Western blot or PCR would suffice. But the fact…
In the last post I talked about p-values and how we define significance in null hypothesis testing. P-values are inherently linked to degrees of freedom; a lack of knowledge about degrees of freedom invariably leads to poor experimental design, mistaken statistical tests and awkward questions from peer reviewers or conference attendees. Even if you think…
In previous articles, I’ve primed you on hypothesis testing and how we are forced to choose between minimising either Type I or Type II errors. In the world of the null hypothesis fetish, the p-value (p) is the most revered number. It may also be the least understood. The p-value is the probability, assuming the…
Microarrays are one of the most in-depth ways of determining cellular gene expression levels of thousands of genes simultaneously. They are able to help determine: Getting good microarray results starts way before analyzing your data, however. A crucial first step in setting up a good microarray experiment is extracting high-quality RNA from your cells. In…
For applications such as site-directed mutagenesis, it is often recommended that you use a proofreading polymerase (also known as high-fidelity polymerases) to minimize the risk of introducing unintended point mutations. But what is a proofreading polymerase? What makes them different from other polymerases? And when should you use them? Read on to learn more… What…
Before starting any new research project, it’s essential that you have as complete an understanding as possible of the current research literature. Knowing what other people have done will prevent you from duplicating existing work, and will perhaps indicate under-explored niches. If you work in the same subject area over a number of years, you…
Most site-directed mutagenesis protocols strongly recommend that you use only PAGE- or HPLC-purified primers to mutate plasmid templates. Using purified primers is supposed to minimize the introduction of unintended mutations, thus drastically improving the probability of generating your desired mutant. However, specially purified primers can be extremely expensive, and take longer to synthesize than standard…
RNA interference (RNAi) may have originated as a defense mechanism to protect cells against foreign genes introduced by viruses. This concept has since been put to use to create a powerful experimental tool for investigating gene function in organisms. Small-interfering RNA (siRNA) libraries for investigating genome-wide function can be produced by chemical synthesis of probes…
ELISAs (enzyme-linked immunosorbent assays) are often used for detecting and quantifying substances such as peptides, proteins, antibodies and hormones in research and diagnostics. Today, a wide range of ELISA formats exist to suit your needs e.g. indirect ELISA, direct ELISA, competitive ELISA and sandwich ELISA. While it has become easier to perform ELISAs, thanks to…
You have been toiling away at your thesis project for years and you think the end is in sight. Now the big question is “What’s next?” If you think you might want to move away from the bench, then you should check out our suggestions for alternative careers for scientists. If you think your future…
Merriam-Webster defines networking as “the cultivation of productive relationships for employment or business”. Less formally, networking is actively communicating with the other people you know (mostly scientists, in our case) for career advice and job openings, in addition to utilizing opportunities to meet new people for the same purpose. This is a core activity of…
Although the microscope is probably the most commonly used biological instrument, it is frequently used improperly. The rate-limiting step to getting high quality microscopic images is illumination of your specimen. When you examine a specimen under the microscope, the intensity and distribution of light must be clear and equal to enable you to evaluate all…
Several years ago as a freshman in a research lab, the very first project I received was to pipette incremental micro-volumes of H2O onto a piece of parafilm. Boring! Weighing the liquid on parafilm and comparing the weight between 10 replicates for each micro-volume continued for a week before I touched anything else in that…
You might be proud of your pipetting skills (if not, check this article on how to stop pipetting errors from ruining your experiments) and be churning out data faster than a liquid handling robot, but beware… you might also be pipetting yourself out of a job. I almost did. Pain due to pipetting is common….
The presence of supercoiled plasmid DNA on a gel can be inconvenient for molecular biologists, especially beginners because it is easy to misinterpret. Read our top tips how to recognize supercoiled DNA and keep it from derailing your cloning experiments.
If you’re starting your PhD or post-doctoral work, chances are you’ll need to use a light microscope at some stage during your research. Some of you may be seasoned microscopists. For many of you though, this might be the first time you’ve ever plugged in a microscope, or at least the first time you’ve used…
Everyone loves a bargain! These days, more and more labs need to stretch every dollar as far as it will go. So how do you keep your lab well-supplied on a tight budget? To get a better deal on products you might choose to shop around, buy in bulk or haggle with vendors. However, if…
They say scientists are highly skilled… and rightly so! While many people would think that we’re shy, retiring types who sit at our lab benches obsessing over teeny-weeny molecules, science (and particularly the process of obtaining a PhD) sets us up as highly skilled members of the workforce. I can hear you all groaning as…
ChIP-seq is a wonderful technique that allows us to interrogate the physical binding interactions between protein and DNA using next-generation sequencing. In this article, I’ll give a brief review of ChIP and introduce the chromatin immunoprecipitation sequencing technique (ChIP-seq), which combines ChIP with next-generation sequencing. What is chromatin immunoprecipitation? Chromatin immunoprecipitation (ChIP) allows us to…
“While I dance I can not judge, I can not hate, I can not separate myself from life. I can only be joyful and whole. This is why I dance.” – Hans Bos While in graduate school, I tried really hard to find an activity that would allow me to disassociate my body from my…
If your immunohistochemistry is not working quite as expected, don’t fret. Check out this comprehensive guide to troubleshooting immunohistochemistry.
Have you ever wished you could transfer the same SDS-PAGE gel twice? Sometimes, when you are blotting for many different proteins of similar size, stripping and reprobing multiple times can become impractical. Here’s a simple diffusion transfer method that can be used to generate duplicate membranes from a single gel: Protein transfer by this diffusion…
Phosphorylation is one of the major post-translational modifications that regulate the activity of a protein. Around a third of human proteins are believed to be phosphorylated, and so the kinases and phosphatases that mediate protein phosphorylation are of major interest to biomedical researchers. However detecting protein phosphorylation can be difficult, particularly from cell extracts. Phospho-specific…
This column is loaded with pop quizzes for you to test yourself on. If you haven’t already done so, catch up on yesterday’s piece on hypothesis testing for a refresher. Take a gander at the table below for a summary of the two types of error that can result from hypothesis testing. Type I Errors occur…
Hypothesis testing is the foundation around which we prove our science is worth funding, publishing and sitting through a conference presentation for. I can’t overstate the importance of understanding hypothesis testing, such is the integral part it plays in biological analyses. The Null Hypothesis Fundamental to statistics is the concept of a null hypothesis, and…
Back in August I shared my training regimen for guesstimating the OD600 readings of microbial cultures with superhuman accuracy. Although my method is effective, I will admit that it has two shortcomings: you need to make a separate standard curve for each container type, and guesstimation is not an officially sanctioned scientific method. But now,…
If you use a human cell line in your research, have you wondered where, or who, it came from? I never gave it much thought, until I read Rebecca Skloot’s book, The Immortal Life of Henrietta Lacks. In 1951, cervical tumour cells were taken from Henrietta Lacks and put into culture, to divide endlessly and…
For a long time we’ve been able to pinpoint the subcellular location of proteins, and the advent of FISH (Fluorescence in situ Hybridization) allowed us to locate the position of genes in the nucleus, but recent advances in RNA FISH are making it easier and easier to collect the same data about individual messenger RNAs….
In this, the first in a series of articles on statistics, I want to set out some of the main reasons why you, as a biologist, should improve your knowledge of statistics. The general consensus is that biologists are not strong when it comes to statistics. There’s nothing in our brains that stops us from…
We have previously discussed some of the pros and cons of moving countries for a new research position. If you’ve made the decision to take the plunge and move abroad, here are 5 tips from a seasoned scientific wanderer. While I was doing my Master’s degree in Biotechnology, I decided on something – I would…
Previously, I introduced the DNA microarray technology and described the principle behind it: hybridization between the nucleic acid sequence from the biological samples being examined and a synthetic probe immobilized and spatially arrayed on a solid surface, the microarray. In this article, I will explain how these probes are designed and positioned on the array. I…
You’ve spent a few years optimising your experiments and gathering data, and with good planning, “The easier way to write a PhD thesis,” it’s all come together, and you’re ready to start writing it up. This is the last big challenge in getting your PhD finished, but it’s the part that can feel the most…
Do you want to immunoprecipitate (IP) a protein with a molecular weight that is anywhere near 55 kDa or 25 kDa? Then you have an irritating problem to deal with: antibody co-elution. But don’t panic, we have six strategies for dealing with your new problem. The Problem: Typically, the IP antibody is bound to Protein…
When it comes to writing up a research paper, there are many ways to go about it. If it’s just you doing most of the writing, with your supervisor, it is quite straightforward – you can just maintain a single copy of the document and exchange it by email. Software like Microsoft Word can track…
Working with RNA is definitely an acquired skill. It’s a lot more finicky than working with DNA, and requires careful attention to detail in order to avoid disastrous through RNase contamination. Here are a few common ways to lose your hard-earned RNA: 1. Don’t keep everything on ice Keeping the temperature of all of your reagents cool is…
Any research biologist spends a large amount of their working time at the computer, whether it’s writing articles, analysing data or just checking emails. In fact, any new research proposal will likely start by trawling Pubmed and online databases to get the latest information on a particular topic. But have you ever stopped to think…
Restriction enzymes are a basic tool in the molecular biologist’s arsenal. They’re super easy to use, and virtually essential for cloning and other applications. Restriction enzymes are also a great example of a perfect “tool” from nature that scientists have co-opted for their own use. Here are a few fun facts about restriction enzymes that…
Good organization is essential for keeping a lab in good running order. Databases of strains, plasmids, primers, and stocks are useful for keeping track of your materials, and allow your work to be continued easily after you’ve left the lab. In this article, I’ll talk about a few tools in Microsoft Excel that will make…
It’s time to start thinking about your next move. Maybe you’ve finished your undergrad/master’s degree and are considering doing a PhD. Or maybe you’re past all that and need to find a post-doc position. Amongst all of this, you might be considering the option of doing your PhD or post-doc in a foreign country. It’s…
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