RNA purification may be a common procedure in molecular biology but it is by far the one that people fear most.

Why? Dreaded RNase.

It’s everywhere… all over your bench and pipettors, and floating in the air, waiting for the chance to creep into your prep, shred your RNA into nucleotides, and ruin a day’s work.

Well, not really. It’s true that extra precautions need to be taken for RNA preparation, but as long as you follow some basic good laboratory practices, RNase contamination need not a problem. In contrast to Nick’s paranoid outlook, I suggest a more relaxed approach to RNA purification. Read more »

Myosin II functions as a molecular motor which facilitates contraction of the actin cytoskeleton during migration, resides outside of protrusions at the front of motile cells, and acts at a distance to impact cell protrusion, signaling, and maturation of nascent adhesions. So clearly myosin II is a protein that is of great importance for understanding cell migration.

But Myosin II is not just one protein. There are actually two isoforms of this protein that are not identical, just very very similar. I’m not familiar with where in the natural history of cells the genes for these two proteins diverged, but they’re clearly derived from a single ancestral gene. And beyond that, there are quite a few other myosins which are more distantly similar (the list easily goes into double-digits)¹.

Vicente-Manzanares et al.², in their paper, determine the divergent functions of myosin IIA (MIIA) and MIIB, and find that these isoforms have become suited to spatial and functional niches within the cell. They found: Read more »

As genetic screening becomes increasingly advanced and personal genomes become more commonplace, the potential for genetic engineering and modern eugenics is becoming a reality. “Designer babies” may not be science fiction forever, creating an ethical dilemna on the horizon.

Hsein-Hsein keeps us informed on personalized sequencing companies that are coming out, including 23andMe, deCODEme, and Navigenics, and now the first whole genome squencing company, Knome. The goal for some is to one day sequence genomes for $1000, putting it within the reach of average consumers.
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Lysis of some microbes is easy, but for others its much more difficult - I think due to differences in the make-up of their cell wall.

At the moment, one of my colleagues is preparing hundreds of cell-free extracts from microbes isolated from the environment to screen for interesting enzyme activities. Since she is processing a wide range of microbes she has to use a method that will lyse all of them - even the most difficult ones.

Unfortunately that means using glass beads and a lot of vortexing to mechanically break the cells. I say unfortunately because not only does it take her a very long time to process all of her samples, but she has a very noisy vortex mixer, which is driving me crazy!

Yesterday I came across something that could be the answer to both of our prayers. Read more »

Ethanol precipitation is a commonly used technique for concentrating and de-salting nucleic acid (DNA or RNA) preparations in aqueous solution. The basic procedure is that salt and ethanol are added to the aqueous solution, which forces the nucleic acid to precipitate out of solution. The precipitated nucleic acid can then be separated from the rest of the solution by centrifugation. The pellet is washed in cold 70% ethanol then after a further centrifugation step the ethanol is removed, and the nucleic acid pellet is allowed to dry before being resuspended in clean aqueous buffer. So how does this work? Read more »

On a couple other blogs, a study published in Science by Joan Steitz¹ is being called “One of the biggest findings of the year,” and “If it turns out to be true, this finding just flipped the whole field on its head.” Bitesize Bio would be greatly remiss to not mention to so hot a story, joining in with The Daily Transcript and One Random Scientist.

The abstract, from Switching from Repression to Activation: MicroRNAs Can Up-Regulate Translation: Read more »

No matter how efficient you are, it’s always possible to improve your productivity and improving your productivity means that you get more of the rewards you are trying to obtain: results, publications… or dare I say it, money.

Here are 20 ways to improve your productivity. Some are focussed toward improving the productivity of bench research, but most are applicable in many other jobs. This list is based on much longer general list that can be found at Steve Pavlina’s excellent personal development website. Read more »

There might be more to cell death besides apoptosis and necrosis. In a paper that sounded a bit fishy to me, Michael Overholtzer, Joan Brugge and coworkers¹ introduce “Entosis”: A non-apoptotic cell death process, that occurs by cell-in-cell invasion.

As Eileen White² described:

Upon examination of mammary epithelial cell lines in suspension, Overholtzer et al. noticed the presence of cells within other cells. Further investigation of this phenomenon revealed that detachment of mammary epithelial cells from the ECM initiates a new pathway of nonapoptotic cell death called entosis in which one cell invades into another.

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