How to Troubleshoot Problems with Fluorescently Tagged Proteins
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How to Troubleshoot Problems with Fluorescently Tagged Proteins

Using fluorescent proteins as imaging probes is a widespread and versatile technique in microscopy. You can use them in a wide range of living systems, from single cultured cells to complete organisms and animals. Fluorescently tagged proteins can be used to track and examine real-time localization, interactions, and translocation of your protein of interest, as…

Live-Cell Imaging: Choosing the Right Technique
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Live-Cell Imaging: Choosing the Right Technique

If you want to see in real time what is going on inside your cell then you should be performing live-cell imaging. Live-cell imaging techniques allow real-time examination of almost every aspect of cellular function under normal and experimental conditions. With all live-cell imaging experiments, the main challenges are to keep your cells alive and healthy…

Catch of the Day: A Look into Different FISH Techniques

Catch of the Day: A Look into Different FISH Techniques

You are probably familiar with fluorescent in situ hybridization (FISH) to detect and localize the presence or absence of specific DNA sequences on chromosomes. But did you know there are numerous FISH experiment variations? Including high-resolution FISH and quantitative FISH? Read here about Fiber-FISH, Q-FISH, and Flow-FISH and decide if you would like to undertake one of…

Vitamin H and Egg White: Streptavidin-Biotin for Immunohistochemistry

Vitamin H and Egg White: Streptavidin-Biotin for Immunohistochemistry

If you want to make molecules stick together you need to know about streptavidin/biotin. This article follows on from Mike’s article looking at ‘sandwich’ and ‘amplification’ methods of immunohistochemistry (IHC) and covers how streptavidin-biotin works in IHC, including protocols. Streptavidin-Biotin What is it? Avidin is a natural biotin-binding protein found in egg whites. Streptavidin is similar…

Create Publication Quality Fluorescence Microscopy Images with the Help of Leica Microsystems’ Science Lab Resource
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Create Publication Quality Fluorescence Microscopy Images with the Help of Leica Microsystems’ Science Lab Resource

Have you ever been shown how to use a microscope properly? Or do you just dive right onto the microscope with little or no training and scant knowledge of the basics, then twiddle knobs, snap photos and expect the publication-quality images to appear? If it’s the latter you are certainly not alone! If only there…

PIER, HIER and Mannich: Antigen Retrieval in Immunohistochemistry

PIER, HIER and Mannich: Antigen Retrieval in Immunohistochemistry

When you fix your tissue samples with paraformaldehyde (PFA) the proteins in your sample become covalently cross-linked. This is good to preserve the ‘architecture’ of your tissue sample. However, this cross-linking can become a problem when you carry out immunohistochemistry (IHC). Cross-linking can ‘mask’ or hide your antigens-of-interest and make them ‘invisible’ to your IHC…

Microscope maintenance: changing and aligning your mercury burner
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Microscope maintenance: changing and aligning your mercury burner

Mercury burners are one of the most common light sources used in fluorescence microscopes, producing a wide spectrum of wavelengths making them a great light source for viewing your samples. But they do have their issues – one of which is their propensity to break or become damaged if not used and cared for correctly, which…

The power of STED microscopy, Part 1: How does it work?

The power of STED microscopy, Part 1: How does it work?

Do you suspect that your favourite protein is doing something really cool? But you cannot see it because your confocal microscope’s resolution is limited. Then Stimulated Emission Depletion (STED) microscopy is what you need! With the power to smash through the diffraction limit of confocal microscopy, STED opens up a whole new world of improved…

Is There Overlap? Find Out with a Proximity Ligation Assay

Is There Overlap? Find Out with a Proximity Ligation Assay

Colocalization blues (and reds and greens) Trying to find if and where two epitopes co-localize (or, to be more precise, where they are found in close proximity) may seem easy at first: 1) Bind your two epitopes with primary antibodies from two different species, 2) bind these primary antibodies with two secondary fluorescent antibodies, one…

Digital Pathology – why you need it and how to choose the best camera for it

Digital Pathology – why you need it and how to choose the best camera for it

Yup, we really are in the digital age…even the pathology is digital. Facebook, Instagram, Tumblr. It has never been easier to take pictures and share them. The digital revolution is upon us and nothing is safe, even your pathology samples. Digitizing your pathology samples can help you better organize and manage pathology for later. And…

Looking good! A Guide to Adjusting and Maintaining Microscope Eyepieces

Looking good! A Guide to Adjusting and Maintaining Microscope Eyepieces

The magnification and viewing of samples using a microscope relies on both the objectives and the eyepieces working harmoniously together. If you buy a ready-to-use microscope, then the objectives and the eyepieces which are fitted as standard will be designed to complement each other. On the other hand, if you are designing and building a…

I Can See (See Dee)! CCD and CMOS Cameras for Microscopy

I Can See (See Dee)! CCD and CMOS Cameras for Microscopy

Two different sensors are generally used in cameras for microscopy: Charge Coupled Devices (CCD) or Complementary Metal Oxide Semiconductors (CMOS or sCMOS). Although there are a number of similarities between the two sensors, differences in the way they function can have an effect on image capture time as well as signal-to-noise ratio. Let’s take a…

Analysing Microscopy Images? What You Should Know About Dynamic Range: Part 2

Analysing Microscopy Images? What You Should Know About Dynamic Range: Part 2

In the first part of this article (you can read it here), we looked at clipping and saturation in terms of microscope images, followed by a definition of Dynamic Range and an introduction to Bit Depth. Intrascene Dynamic Range The dynamic range which can be detected at the same time in the same field of…

Analysing Microscopy Images? What You Should Know About Dynamic Range: Part 1

Analysing Microscopy Images? What You Should Know About Dynamic Range: Part 1

Ever tried to turn the volume all the way up on a small radio or small stereo system? (Hopefully you have not tried it with earphones in!) Notice how, after some point, the sound didn’t get any louder- it just got more distorted? That’s because you’ve hit the ceiling of your machine’s dynamic range.  It’s…

Two Photon Confocal Microscopy: What it is and How to Use it to Your Advantage

Two Photon Confocal Microscopy: What it is and How to Use it to Your Advantage

“A two photon microscope has higher sensitivity than a normal confocal microscope, because it uses two photos instead of one!”  Yes, I can bear witness that this phrase has actually been uttered, and it was not by an undergraduate student. No exception to the rule The condensation of various levels of misunderstandings in this statement…

Dots, Probes and Proteins: Fluorescent Labels for Microscopy and Imaging

Dots, Probes and Proteins: Fluorescent Labels for Microscopy and Imaging

If you remember from one of my previous articles (if not, you can read it here!), we introduced ‘fluorophores’. These are basically substances (natural or synthetic) which have the ability to absorb light at a low wavelength and re-emit at a higher wavelength. In other words- they fluoresce! In this article, I’ll introduce the three…

Can’t See the Mouse for the Mice?! Solutions to Mouse-on-Mouse Immunohistochemistry Detection

Can’t See the Mouse for the Mice?! Solutions to Mouse-on-Mouse Immunohistochemistry Detection

The issue of mouse-on-mouse background is only a cause for concern for the histotechnologist working within a research environment. Those working in a diagnostic setting will probably never experience this as they will be working with human tissue with antibodies raised in a variety of species- but one species that won’t be used is human!…

Fluorescence 101: A Beginners Guide to Excitation/Emission, Stokes Shift, Jablonski and More!
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Fluorescence 101: A Beginners Guide to Excitation/Emission, Stokes Shift, Jablonski and More!

You may already use fluorescence as a tool in your microscopy and imaging work, but, do you know exactly what it is? Why are certain proteins and probes fluorescent? What causes this light emitting property? We’ll have a look at these and more questions in this article. Start with a definition We’ll start with a…

“Where the hell did my signal go?”  AKA The Problems (and Uses) of ‘Photobleaching’ in Microscopy and Imaging

“Where the hell did my signal go?” AKA The Problems (and Uses) of ‘Photobleaching’ in Microscopy and Imaging

Like most things in this world, fluorophores are mortal, and eventually your once bright fluorescent image will inevitably fade to black. This fading or ‘photobleaching’ of fluorescent signal can make imaging difficult, especially if you are trying to take quantitative images. Read below to learn what causes photobleaching of your fluorophores and how best to…

Light Through Crystals: What Exactly is Differential Interference Contrast Microscopy?

Light Through Crystals: What Exactly is Differential Interference Contrast Microscopy?

Although his name could fit in easily to the early 1980’s Hip-Hop Scene, Jerzy Nomarski (or ‘George’) was actually a Polish physicist with an interest in optical theory. Born in 1919, he eventually became a member of the Polish Resistance fighting in the Second World War. He was captured by enemy forces and held as…

The Many Flavors of Widefield Microscopy

The Many Flavors of Widefield Microscopy

While confocal microscopy seems to have become pervasive in cell biology, widefield microscopy techniques still have a special and important place. This month on the Microscopy and Imaging Channel, we’re focusing on widefield microscopy techniques: covering the basics of what these techniques are and when you should turn to them. What is this ‘Widefield’ you…

Catching Waves: What a Microscopist Ought to Know About Phase Contrast

Catching Waves: What a Microscopist Ought to Know About Phase Contrast

Phase contrast microscopy is a light microscopy technique which is primarily used to visualise live cells. Using various filters and condensers, the image produced by phase contrast allows us to see greater detail in live cells and can highlight aspects such as intracellular structures. Keep your cells alive! The best way to view cells is…

This One’s Upside Down! Inverted and Stereo Microscopes in Bioscience Laboratories

This One’s Upside Down! Inverted and Stereo Microscopes in Bioscience Laboratories

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…