What Does Oil Red O Stain? Oil Red O (‘ORO’) is used to demonstrate the presence of fat or lipids in fresh, frozen tissue sections. Introduced by French in 1926, ORO is a fat-soluble diazo dye, and is classified as one of the Sudan dyes which have been in use since the late 1800s. Like [...]

What is Prussian Blue? Prussian blue (PB) was actually the first synthetic color to be discovered during the Industrial Revolution. It was developed accidentally in 1704 by a chemist who was trying to produce another color. It wasn’t used as a histochemical stain until 1867 when its original formula was described by German pathologist, Max [...]

Following on from Part 1, we’ll now take a look at the actual use of geometric probability in stereology, as well as the advantages and disadvantages of this technique. As you’ll know from the two-part introduction (here and here), stereology looks at the relativity between an object and its sections, while geometric probability allows a [...]

The study of geometric probability in stereology may seem like a large, overwhelming area of focus but, don’t panic, it’s not! In fact, it is a very specific field that is likely to come easy to those that excel in mathematics or science (yes that means you). However, the concept is not one that most [...]

Last week I used a bit of math to show you how spectrophotometry works to measure nucleic acid concentration and purity. This week I am going to talk about how fluorescence is used two different ways to analyze nucleic acids. Spectrofluorometry Nucleic acids can bind fluorescent dyes such as Hoechst or PicoGreen™ (specific for dsDNA). [...]

New sequencing technologies are largely funded with the hope that the next technology will take sequencers into the diagnostics world. This requires overcoming two present hurdles: cost per base and turnaround time. At the Advances in Genome Biology and Technology conference held at Marco Island, 2012, Oxford Nanopore Technologies introduced its USB size sequencer ‘MinION’, [...]

If you’re reading our Microscopy and Imaging Channel here on BitesizeBio, you might have heard about the new techniques which fall under the umbrella of ‘Super-Resolution Microscopy’. In her recent article, Cynthia introduced us to the limits of resolution and how this can be overcome. Question time You may have more questions; What are the [...]

What is Congo red? Did you know that Congo red (CR) originally started out as a textile dye? It belongs to the azo class of dyes- synthetic compounds that are among the most popular dyes used in the clothing and fashion industry. CR is a benzidine derivative which can react with structural polysaccharides- including the [...]

Why do I see a cloud? When you are looking at protein localization within a cell, have you ever wondered why you see a cloud of fluorescence rather that several individual fluorescent points? Well, light microscopy has a theoretical resolution limit of 200 nm. This means that in theory, to resolve two points as being [...]

 What Does Acid-Fast Stain? Acid-Fast (AF) is an important special staining technique used in the histology lab. This is adifferential stain used to identify acid-fast bacterial organisms, such as members of the genus Mycobacterium and Nocardia. The discovery of TB German scientist and physician, Robert Koch, was a Nobel Laureate in Medicine and a founder of the science of bacteriology. [...]