Isolating pure DNA is key to many downstream applications for molecular biologists.  Isolating large quantities of pure DNA used to be a laborious task.  But thanks to commercially available kits, older methods have been streamlined to allow efficient recovery of pure DNA. In this article, I will talk about a method called DNA gel extraction, [...]

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). [...]

So you’ve isolated your DNA or RNA from your favorite sample. And now, if you are anything like me, the first thing you’ll do is scramble to check the quality and concentration of your extract. You have a few different options at your disposal to perform this crucial analysis, which will let you know whether [...]

Despite obvious differences between the Korean professor-biotechnologist Hwang Woo-suk and German-born postdoc Jan Hendrik Schön, who used to work in the US on semiconductors, both of these scientists have something in common. Since Hwang Woo-suk’s and Schön’s groundbreaking articles were published in Nature and Science, nobody has been able to reproduce their results  and the [...]

It is a truth universally acknowledged that free cheese exists only in a mousetrap, and even there it’s free only to the end user. So it’s no wonder that the traditional system of most scientific publications through publishing houses seems to be fair. A publishing house (PH) employs editors as well as technical personnel to [...]

2D gel electrophoresis (2DE) is a key technique for purifying individual proteins from complex samples based on their isoelectric points and molecular weights.  Simple enough in theory, but as the plethora of protocols and articles shows, 2DE demands patience and meticulous optimization.  But whether your samples are human sera or HUVEC lysates, 2DE uses these [...]

If you have ever worked with RNA, you know about DEPC (diethylpyrocarbonate). You add it to water at a concentration of 0.1%, shake or stir, incubate at 37°C for two hours or at room temperature overnight and, as if targeted by a magic bullet, the RNAses that may have been in the water are gone. [...]

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.  [...]

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 [...]

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 [...]