Don’t Wave Goodbye to Your Tissue Slices

Don’t Wave Goodbye to Your Tissue Slices

Coating (or ‘subbing’) slides for immunohistochemistry can be the difference between having an organized set of tissue slices ready for microscopy- or watching them detach and float away during a wash. It takes a lot of time to place tissue slices in correct anatomical order, aligned right-side up and flat. To the naked eye, all…

Rubbing Your Microscope’s Eyes: A Guide to Optical Resolution

Rubbing Your Microscope’s Eyes: A Guide to Optical Resolution

Ever wake up especially groggy in the morning, finding it takes a few minutes and a few eye rubs to be able to decipher the numbers on your alarm clock? Our eyes have the ability to resolve an image, so that you can observe separate objects and details. Similarly, microscopes have a parameter of resolution:…

Tissue Embedding and Sectioning: Something to Think About Whilst in the Bath.

Tissue Embedding and Sectioning: Something to Think About Whilst in the Bath.

In the same way that you should ‘Think Before You Fix’, the choice of embedding media should be dictated by your required end-point. The basic principle is that by processing tissue into an embedding medium you harden the tissue and provide support protecting it from the mechanical forces associated with sectioning. Parma ham and steak…

Excited?! Emitting Light?! An Introduction to Fluorescent Microscopy

Excited?! Emitting Light?! An Introduction to Fluorescent Microscopy

Fluorescent-based microscopy techniques are some of the most common ways to visualize biological structures. Almost any protein- or nucleic acid-based molecule can be tagged with a fluorescent marker or dye and subsequently detected by a light microscope. This fluorescence is seen as a bright object against a black background, allowing for intense and clear images. …

A Microscopy Glossary Part 2: ‘Confocality Means….’

A Microscopy Glossary Part 2: ‘Confocality Means….’

Dichroic Mirror/Filter This is a semi-reflective filter which can also be referred to as ‘dichromatic beam splitter’. Unlike the Longpass filters which absorb light which is not transmitted (see Part 1 of the Glossary), these filters reflect light at lower wavelengths and transmit light at wavelengths above the ‘cut-on’ wavelength. As beam splitters, they are…

A Microscopy Glossary Part 1: ‘What Is This LP650 You Talk About?!’

A Microscopy Glossary Part 1: ‘What Is This LP650 You Talk About?!’

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…

Microscopists: Have you Tried Trichrome?

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…

Which Light Microscope Will I Choose? Part 2- Confocal Systems

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…

Which Light Microscope Will I Choose? Part 1 – Basic Light and Fluorescence Systems

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…

The Cell: An Image Library – An Overview of an Award-winning Multimedia Site

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…

An Introduction to Special Stains

An Introduction to Special Stains

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…

How to Transform Your Images from Mediocre to Publication Quality with Köhler Illumination

How to Transform Your Images from Mediocre to Publication Quality with Köhler Illumination

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…

The Poor Man’s Polariser…Got Shades?

The Poor Man’s Polariser…Got Shades?

I recently introduced you to the concept of polarising microscopy. Naturally, if evaluating refractile material is an everyday part of your research, it is definitely worth investing in a professional polariser modification for your microscope. But if you only use a polariser occasionally, this might not be the best use of your lab’s money. In…

The Perfect Slice: Preparing Tissue Samples For IHC

The Perfect Slice: Preparing Tissue Samples For IHC

When you stop to think about it, tissue slices for immunohistochemistry (IHC) undergo quite a lot of handling. From chemical reactions to washes – even manipulations and transfers between baskets and microtubes – final analysis is often hours away from the initial step of taking a tissue slice. Properly fixed tissue has to be robust…

What You Ought To Know About Polarising Light Microscopy

What You Ought To Know About Polarising Light Microscopy

Polarising microscopy involves the use of polarised light to investigate the optical properties of various specimens. Although originally used predominantly in the field of geology, it has recently become more widely used in medical and biological research fields too. Polarising light microscopy is a contrast-enhancing technique to allow you to evaluate the composition and three-dimensional…

How Köhler Illumination Can Help You See The Light

How Köhler Illumination Can Help You See The Light

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…

What Everybody Ought to Know About the Light Microscope

What Everybody Ought to Know About the Light Microscope

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…

It’s 10 am. Do You Know Where Your mRNAs Are?

It’s 10 am. Do You Know Where Your mRNAs Are?

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….